Fuel and Process for Powering a Compression Ignition Engine

ABSTRACT

A process of powering a compression ignition engine using a main fuel comprising methanol and water, including: fumigating an intake air stream with a fumigant comprising an ignition enhancer; introducing the fumigated intake air into a combustion chamber in the engine and compressing the intake air; introducing the main fuel into the combustion chamber; and igniting the main fuel/air mixture to thereby drive the engine. Also provided a fuel for use in the process, a two-part fuel for use in the process, and associated power generation systems.

The present invention relates to a fuel and process for powering acompression ignition type of internal combustion engine.

This application claims priority from Australian patent applicationsAU2010905226 and AU2010905225. This application is also related to anInternational application entitled “Process for powering a compressionignition engine and fuel therefor” filed by the same Applicant on thisday with a common priority claim. The specification of the relatedInternational application is herein incorporated by reference.

BACKGROUND OF THE INVENTION

The pursuit for fuel alternatives to conventional fossil fuels isprimarily driven by the need for a ‘clean’ emissions fuel coupled withlow production costs and wide availability. Much attention is paid tothe environmental impact of fuel emissions. Research into alternativefuels focuses on fuels that will reduce the amount of particulate matterand oxides produced by fuel combustion as well as fuels that reduce thenon-combusted fuel and CO₂ emissions and other products of combustion.

The drive for environmentally friendly fuel compositions for transportapplications has focused on ethanol. Bio-materials such as organic plantmatter can be converted into ethanol, and ethanol produced by suchprocesses has been used as a partial replacement of fuels for sparkignition engines. Whilst this reduces the reliance on non-renewableresources for fuels, the environmental outcomes arising from the use ofthese fuels in engines has not been substantially improved in an overallsense, with cleaner combustion being offset by continuing use of suchfuels in lower efficiency spark ignition engines, and negativeenvironmental impact associated with the use of energy, arable land,fertilisers and irrigation water to create fuel.

Other fuel alternatives for complete or partial replacement oftraditional fuels have not become widely used.

One major disadvantage with the complete replacement of traditionalfuels, and in particular fuels for compression ignition engines (dieselfuels), with a renewable replacement fuel, relates to the perceivedproblems associated with the low cetane index of such fuels. Such fuelspresent problems for achieving ignition in the manner required forefficient operation of the engine.

The present applicants have also recognised that in some remotelocations or environments, water is a scarce resource, and in suchlocations there can be a demand for power generation (such as throughdiesel engine electricity generation) coupled with water by-productcapture for re-use in the local community. In addition moving bulkenergy via liquid pipeline is a long standing and cost effectivetechnique for moving large quantities of energy over long distances withminimum visual impact, compared to overhead transmission lines.

The present applicants have also recognised a need in some locations forheat generated in such industrial processes to be captured and re-usedin the local community. In some instances this need is coupled to theneed for water capture for reuse, referred to above.

In summary, there is a continuing need for alternative fuels for use ininternal combustion engines. Fuels that can reduce emissions are ofinterest, particularly where the improved emissions profile is obtainedwithout a major adverse impact on fuel efficiency and/or engineperformance. There is also a need for methods of powering compressionignition engines that enable such engines to be run on dieselreplacement fuels containing components not traditionally thought to besuitable for use in such applications. There is additionally a need fordiesel engine fuels and engine operation methods that are suited to usein remote locations, or in environmentally sensitive environments (suchas in high latitude marine environments particularly in port areas interms of emissions) or other areas such as remote dry but cold inlandareas that can make maximum use of all by-products of the engineoperation, including, for example, the heat and water by-products. Theseobjectives are preferably addressed with as little as possible penaltyto fuel efficiency and engine performance.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided a process ofpowering a compression ignition engine using a main fuel comprisingmethanol and water, including:

-   -   fumigating an intake air stream with a fumigant comprising an        ignition enhancer;    -   introducing the fumigated intake air into a combustion chamber        in the engine and compressing the intake air;    -   introducing the main fuel into the combustion chamber; and    -   igniting the main fuel/air mixture to thereby drive the engine.

According to the present invention there is also provided diesel enginefuel for use in a compression ignition engine which is fumigated with afumigant comprising an ignition enhancer into an air inlet of theengine, the fuel comprising methanol, water, and one or more additivesselected from the group consisting of: ignition improvers, fuelextenders, combustion enhancers, oxygen absorbing oil, lubricityadditives, product colouration additives, flame colour additives, anticorrosion additives, biocides, freeze point depressants, depositreductants, denaturants, pH controlling agents, and mixtures thereof.

The invention can result in simplification and a lower cost of fuelmanufacture and reduced environmental impact by elimination of the needfor production of high purity components and by-product components, byacceptance of a blend of such components into a fuel according to themethods described herein. Cost and environmental benefit may also arisefrom the use of fuel in cold climates, since the freezing point of thefuel can readily meet any low temperature environments likely to beencountered.

The exhaust resulting from fuel combustion may contain low impurities,making it ideal for subsequent processing. As one example, the CO2 maybe converted back to methanol to directly reduce the greenhouse gas CO2or high purity CO2 can be used for organic growth such as algae formultiple end uses including methanol manufacture, utilizing energysources which can include renewable sources, including solar.

In some embodiments, water generated during fuel combustion can berecovered, which is a major advantage for remote areas where water isscarce. In other instances, heat generated in operation of the dieselengine can be utilised for local area heating requirements. Someembodiments accordingly provide systems for power generation through theoperation of a diesel engine which utilise the water and/or heat outputof the engine in a suitable way.

According to one aspect, there is provided a method for supplying fuelto a compression ignition engine, the method comprising:

-   -   supplying a main fuel composition comprising methanol and water        to a first tank that is in fluid connection to a combustion        chamber of the compression ignition engine, and    -   supplying a secondary fuel component comprising an ignition        enhancer to a second tank that is in fluid connection to an air        intake of the compression ignition engine.

In accordance with another aspect, there is provided a power generationsystem comprising:

-   -   powering a compression ignition engine using a methanol-water        fuel to generate power;    -   preheating an inlet air stream of the compression ignition        engine, and/or fumigating the inlet air stream with an ignition        enhancer;    -   treating engine exhaust to recover exhaust heat and/or water        from the engine, and redirecting the heat and/or water for        further use.

In accordance with a further aspect, there is provided a method oftransporting a two-part pre-fuel composition comprising methanol andether, including transporting the pre-fuel from a first location to asecond location remote from the first location, and separating the etherfrom the methanol to yield a first fuel part comprising methanol, and asecond fuel part comprising ether.

In accordance with a further aspect, there is also provided a pre-fuelcomposition comprising methanol and up to 10% by weight of an ether

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample with reference to the accompanying drawings, wherein:

FIG. 1 is a flow chart illustrating a process for powering a compressionignition engine in accordance with an embodiment of the presentinvention;

FIG. 2 is a graph of the weight % of dimethyl ether (DME), as ignitionenhancer, to be fumigated into an engine (compared to the weight of themain fuel), plotted against the temperature change of the compressedmain fuel/fumigant/air mixture, for three main fuel compositions (100%methanol, 70% methanol:30% water and 40% methanol:60% water). The plotrelates to the situation in the absence of other ignition enhancementtechniques;

FIG. 3A is a flow chart illustrating a process for powering acompression ignition engine and treating engine exhaust, with waste heatused as a separate heating source through a hot water loop;

FIG. 3B is a flow chart similar to FIG. 3A but excluding the step offumigating the engine intake air;

FIG. 4A is a more detailed view in the flow chart of FIGS. 3A and 3B ofthe exhaust treatment;

FIG. 4B is a similar view to FIG. 4A, but without a final exhaust airexchange condenser;

FIG. 5A is a flow chart illustrating a process for powering acompression ignition engine to drive a rail vehicle and treating engineexhaust;

FIG. 5B is a flow chart similar to FIG. 5A but excluding the step offumigating the engine intake air;

FIG. 6A is a flow chart illustrating a process for powering acompression ignition engine to drive a marine vehicle and treatingengine exhaust;

FIG. 6B is a flow chart similar to FIG. 6A but excluding the step offumigating the engine intake air;

FIG. 7 is a graph illustrating the Brake Thermal Efficiency of acompression ignition engine with fumigation of DME using main fuelscontaining varying amounts of water and amounts of methanol, DME and DEEin the liquid phase.;

FIG. 8 is a graph illustrating the Brake Thermal Efficiency of acompression ignition engine using main fuels containing varying amountsof ether as ignition enhancer, and utilizing DME as fumigant.

FIG. 9 is a graph illustrating the NO exhaust output of a compressionignition engine using main fuels containing varying amounts of water andutilizing DME as fumigant.

FIG. 10 is a schematic diagram of the process and instrumentation of thetesting facility used in obtaining the results of Example 1.

FIG. 11 is a graph illustrating the reduction in NO exhaust output of acompression ignition engine by increasing the amount of water in themethanol-water fuel.

DETAILED DESCRIPTION

The fuel and process described herein is suitable for poweringcompression ignition (CI) engines. In particular the fuel and process ismost suitable, but not limited to, CI engines operating at low speedssuch as 1000 rpm or less. The speed of the engine may even be 800 rpm orless, for instance 500 rpm or less. The speed of the engine may even be300 rpm or less, for instance 150 rpm or less. The fuel is thereforesuitable for larger diesel engines such as those operating on ships andtrains, and in electrical power generating plants. The slower speeds inlarger CI engines allows sufficient time for combustion of the selectedfuel composition to be completed and for a sufficiently high percentageof the fuel to be vaporized to achieve efficient operation.

It is however understood that the fuel and process described hereincould operate with smaller CI engines operating at higher speeds. Infact, the preliminary test work was conducted on a small CI engineoperating at 2000 rpm and 1000 rpm, demonstrating that the fuel is alsocapable of powering such higher speed engines. In some instances,adjustments may assist the use of the fuel and process on smaller(higher rpm) CI engines, and some of these are elaborated below.

Fuel Composition

The fuel composition that forms the main fuel for the process comprisesmethanol and water. The fuel is a compression ignition engine fuel, thatis, a diesel engine fuel.

To date, methanol has not found commercial application in compressionignition engines. The disadvantages with using methanol as an enginefuel, either neat or blended, is highlighted by its low cetane index,which is in the range of 3 to 5. This low cetane index makes methanoldifficult to ignite in a CI engine. Blending water with methanol furtherreduces the cetane index of the fuel making combustion of themethanol/water blend fuel even more difficult, and thus it would havebeen considered counter-intuitive to combine water with methanol for usein CI engines. The effect of water following fuel injection is one ofcooling as the water heats up and evaporates, further lowering theeffective cetane.

However, it has been found that a methanol-water fuel combination can beused in a compression ignition engine in an efficient manner and withcleaner exhaust emissions, provided that the engine is fumigated with afumigant comprising an ignition enhancer. Further factors elaboratedbelow also contribute to maximising the effective operation of a CIengine with this fuel.

Methanol has been described for use in fuels compositions previously,but as a heating or cooking fuel, where the fuel is burned to generateheat. The principles that apply to diesel engine fuels are verydifferent, since the fuel must ignite under compression in thecompression ignition engine. Very little, if anything, can be gleanedfrom references to the use of methanol and other components incooking/heating fuels.

The main fuel may be a homogeneous fuel, or a single phase fuel. Thefuel is typically not an emulsion fuel comprising separate organic andaqueous phases emulsified together. The fuel may therefore be emulsifierfree. The accommodation of additive components in the fuel is assistedby the dual solvency properties of both methanol and water, which willenable dissolution of a wider range of materials across the variouswater:methanol ratios and concentrations which can be utilised.

All amounts referred to in this document are by reference to weight,unless specified otherwise. Where a percentage amount of a component inthe main fuel composition is described, this is a reference to thepercentage of that component by weight of the entire main fuelcomposition.

In broad terms, the relative amount of water to methanol in the mainfuel composition may be in the range of from 0.2:99.8 to 80:20 byweight. According to some embodiments, the minimum water level (relativeto methanol) is 1:99, such as a minimum ratio of 2:98, 3:97, 5:95, 7:93,10:90, 15:95, 19:81; 21:79. The upper limit of water (relative tomethanol) in the composition according to some embodiments is 80:20,such as 75:25, 70:30, 60:40, 50:50 or 40:60. The relative amount ofwater in the composition may be considered to be in the “low to mediumwater” level range, or a “medium to high water” level range. The “low tomedium water” level range covers the range from any of the minimumlevels indicated above to a maximum of either 18:82, 20:80, 25:75,30:70, 40:60, 50:50 or 60:40. The “medium to high water” level rangecovers the range from either 20:80, 21:79, 25:75, 30:70, 40:60, 50:50,56:44 or 60:40 to a maximum of one of the upper limits indicated above.A typical low/medium water level range is 2:98 to 50:50, and a typicalmedium/high water level range is from 50:50 to 80:20. A typical lowwater level range is from 5:95 to 35:65. A typical medium level waterrange is 35:65 to 55:45. A typical high water level range is 55:45 to80:20.

Considered in terms of the percentage of water in the entire main fuelcomposition by weight, the relative amount of water in the main fuelcomposition may be a minimum of 0.2%, or 0.5%, or 1%, or 3% or 5%, 10%,12,%, 15%, 20% or 22% by weight. The maximum amount of water in theentire main fuel composition may be 68%, 60%, 55%, 50%, 40%, 35%, 32%,30%, 25%, 23%, 20%, 15% or 10% by weight. Any of the minimum levels maybe combined with a maximum level without limitation, save for therequirement that the minimum level be below the maximum water level.

Based on the test results reported in the Examples, for a desirablebrake thermal efficiency (BTE), the amount of water in the fuelcomposition in some embodiments is between 0.2% and 32% by weight. Theoptimal zone for a peak in brake thermal efficiency for a methanol-watercompression ignition engine fuel is between 12% and 23% water in themain fuel composition, by weight. The range may be incrementallynarrowed from the broader to the narrower of these two ranges. In someembodiments, this is combined with an amount of ignition enhancer in themain fuel composition that is not more than 15% by weight of the mainfuel composition. Details of ignition enhancers are set out below.

Based on other test results reported in the Examples, for a maximumreduction in NOx emissions, the amount of water in the fuel compositionin some embodiments is between 22% and 68% by weight. The optimal zonefor a maximum reduction in NOx emissions is between 30% and 60% water byweight of the main fuel composition. The range may be incrementallynarrowed from the broader to the narrower of these two ranges. Since NOis the main NOx emission component, reference may be made to NOemissions as being the greater proportion, of, or indicative of, theoverall extent of NOx emissions.

In some embodiments, for a desirable balance of fuel properties andemissions, the main fuel composition comprises between 5% and 40% waterby weight of the main fuel composition, such as between 5% and 25%water, between 5% and 22% water. These levels are based on thecombination of test results reported in the Examples.

For the operation of the compression ignition engine with themethanol/water main fuel composition and fumigation, but without otherignition enhancement techniques such as air inlet preheating or blowing,the water content in the fuel may be at the low to medium level,preferably at the low water level. Where the water level is at thehigher end, the process generally benefits from inlet air and/or mainfuel preheating, to overcome the increased cooling effect of theincreased water level in the main fuel composition. Preheating can beachieved by a variety of techniques, discussed in more detail furtherbelow.

The amount of methanol in the total main fuel composition is preferablyat least 20% by weight of the main fuel composition. According to someembodiments, the amount of methanol in the fuel composition is at least30%, at least 40%, at least 50%, at least 60% or at least 70% of thefuel composition. The amount of water in the total main fuel compositionmay be at least 0.2%, at least 0.5%, at least 1%, at least 2%, at least3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, atleast 9%, at least 10%, at least 11%, at least 12%, at least 13%, atleast 14%, at least 15%, at least 16%, at least 17%, at least 18%, atleast 19%, at least 20%, at least 25%, at least 30%, at least 35%, atleast 40%, at least 45%, at least 50%, at least 55%, at least 60%, atleast 65% and at least 70%. As the weight of water in the main fuelcomposition increases it is increasingly more surprising that fumigationof the inlet air with a fumigant overcomes the penalty of water in thefuel in terms of igniting, with smooth operation in terms of COV of IMEPand producing net power out.

The combined amount of methanol and water in the total main fuelcomposition may be at least 75%, such as at least 80%, at least 85%, orat least 90% by weight of the fuel composition. The main fuelcomposition may comprise one or more additives, in a combined amount ofup to 25%, or up to 20% or up to 15% or up to 10% by weight of the mainfuel composition. In some embodiments, the total or combined level ofadditives is not more than 5% of the main fuel composition.

The methanol for use in the production of the main fuel composition maycome from any source. As one example, the methanol may be a manufacturedor waste methanol, or a coarse or semi-refined methanol, or an unrefinedmethanol. The coarse or waste or semi-refined methanol could typicallycontain mainly methanol, with the balance being water and amounts ofhigher alcohols, aldehydes, ketones or other carbon hydrogen and oxygenmolecules arising during the normal course of methanol manufacture.Waste methanol may or may not be suitable depending on the degrees andtypes of contamination. The references in the above sections to ratiosof methanol and water, or amounts of methanol in the fuel composition byweight, refer to the amount of methanol itself in the methanol source.Thus, where the methanol source is a crude methanol containing 90%methanol and other components, and the amount of this crude methanol inthe fuel composition is 50%, then the actual amount of methanol isconsidered to be 45% methanol. The water component in the methanolsource is taken into account when determining the amount of water in thefuel composition, and the other impurities are treated as additives whenassessing the relative amounts of the components in the products, unlessotherwise specified. The higher alcohols, aldehydes and ketones whichmay be present in the crude methanol may function as soluble fuelextender additives.

According to some embodiments, the main fuel comprises a crude methanol.The term “crude methanol” encompasses low purity methanol sources, suchas methanol sources containing methanol, water and may be up to 35%non-water impurities. The methanol content of crude methanol may be 95%or less. The crude methanol may be used directly in the fuel withoutfurther refining. Typical non-water impurities include higher alcohols,aldehydes, ketones. The term “crude methanol” includes waste methanol,coarse methanol and semi-refined methanol. It is a particular advantageof this embodiment that crude methanol containing impurities at higherlevels can be used directly in the fuel for a CI engine withoutexpensive refining. In this case, the additive (ie crude methanolimpurities and other fuel composition additives excluding water) levelsmay be up to 60% of the main fuel composition (including impurities inthe crude methanol). For main fuel compositions using a higher puritymethanol (such as 98% or higher % pure methanol) as the source, thetotal additive level may be lower, such as not more than 25%, not morethan 20%, not more than 15% or not more than 10%.

Any water of a suitable quality can be used as the source of water forthe production of the main fuel composition. The source of water may bewater included as part of un-distilled coarse methanol, or recycledwater, or a crude or contaminated water (for example, sea watercontaining salts) purified by reverse osmosis, purified by activatedsubstances such as activated carbon, or further chemical treatment,deionisation, distillation or evaporative techniques. The water may comefrom a combination of these sources. As one example, the source of watermay be water recovered from the water-rich exhaust of the combustionignition engine. This water may be recovered via heat exchangers andspray chambers or other similar operations. This recovery and reusetechnique enables cleanup of exhaust emissions. The water in this caseis recycled back to the engine with or without any captured unburntfuel, hydrocarbons or particulates or other combustion products beingreturned to the engine and recycled to extinction via looping combustionsteps, or treated by known means of purification. The water may in someembodiments be salt water, such as sea water, which has been purified toremove the salt therefrom. This embodiment is suited to marineapplications, such as in marine CI engines, or for the operation of CIengines in remote island locations.

The water quality will impact corrosion through the supply chain up tothe point of injection into the engine and engine depositioncharacteristics, and suitable treatment of main fuel with anti-corrosionadditives or other methods may in these circumstances be required.

The amount of additives included in the base fuel may take account ofany downstream dilution effects caused by addition of water (forexample) to the fuel.

Additives which may be present in the main fuel composition may beselected from one or more of the following categories, but notexclusively so:

-   1. Ignition improver additives. These may also be referred to as    ignition enhancers. An ignition improver is a component that    promotes the onset of combustion. Molecules of this type are    inherently unstable, and this instability leads to “self start”    reaction leading to combustion of the main fuel component (for    example, methanol). The ignition improver may be selected from    materials known in the art to have ignition enhancing properties,    such as, ethers (including C1-C6 ethers such as dimethyl ether),    alkyl nitrates, alkyl peroxides, volatile hydrocarbons, oxygenated    hydrocarbons, and mixtures thereof.    -   In addition to the typical ignition enhancers, finely dispersed        carbohydrate particles present in the combustion zone following        evaporation of the liquid fuel components prior to ignition may        or may not have a role as ignition enhancer, however such        species present may contribute to more complete and rapid        combustion of the total air/fuel mixture.    -   While additional ignition improvers can be incorporated into the        main fuel, the techniques described herein facilitate ignition        throughout the engine operating range without such additions.        Thus according to some embodiments the main fuel is free of        ignition improver additives. In other embodiments, the main fuel        is free of DME (although it may contain other ignition        improvers). In the case of dimethyl ether as an ignition        improver, according to some embodiments, less than 20%, less        than 15%, less than 10%, less than 5%, less than 3%, less than        1%, or no dimethyl ether is present in the fuel composition. In        some embodiments, the amount of ether (of any type, such as        dimethyl or diethyl ether) in the main fuel composition is less        than 20%, less than 15%, less than 10%, less than 5%.    -   In some embodiments, at least 80% of the ignition enhancer        present in the main fuel composition is provided by one or at        most two specific chemicals, examples being dimethyl ether and        diethyl ether. In one embodiment, an ignition enhancer of a        single chemical identity is present in the main fuel        composition. In one embodiment, at least 80% of the ignition        enhancer in the main fuel composition is constituted by an        ignition enhancer of a single chemical identity. In each case,        the single ignition enhancer that constitutes the ignition        enhancer, or the >80% ignition enhancer component may be        dimethyl ether. In other embodiments, the ignition enhancer        comprises a mixture of three or more ignition enhancers.-   The amount of ignition enhancer in the main fuel composition in some    embodiments is not more than 20%, such as not more than 10% or not    more than 5% of the fuel composition.-   2. Fuel Extender. A fuel extender is a material that provides heat    energy to drive the engine. Materials used as fuel extenders may    have this purpose as the main purpose for its inclusion in the fuel    composition, or an additive material may provide this function and    another function.    -   Examples of such Fuel Extenders are:    -   a) Carbohydrates. Carbohydrates include sugars and starch. The        carbohydrate may be included for fuel extender purposes,        although it may also function as an ignition improver, and/or a        combustion improver. The carbohydrate is preferably        water/methanol soluble, with higher water levels accommodating        greater dissolution of sugar, for example, in the main fuel. An        enriched water (single phase) main fuel composition enables        dissolution of the carbohydrate, such as sugar, however as the        liquid solvent (water/methanol) in the fuel composition        evaporates in the engine, the carbohydrate solute can form        micro-fine high surface area suspended particles of low LEL        (lower explosive limit) composition which will decompose/react        under engine conditions, improving the ignitability of the main        fuel mixture. To achieve improvement in combustibility of the        mixture, an amount of at least 1%, preferably at least 1.5% and        more preferably at least 5% of this carbohydrate additive is        preferred.    -   b) Soluble Fuel Extender additives. Fuel extender additives are        combustible materials. These additives may be added as separate        components or may be part of an undistilled methanol used to        produce the main fuel composition. Such additives include C2-C8        alcohols, ethers, ketones, aldehydes, fatty acid esters and        mixtures thereof. Fatty acid esters such as fatty acid methyl        esters may have a biofuel origin. These may be sourced through        any biofuel sources or processes. Typical processes for their        production involve transesterification of plant-derived oils,        such as rapeseed, palm or soybean oil, amongst others.    -   There may be opportunity to economically increase the level of        fuel extender in the main fuel composition itself for particular        markets where such additive can be produced or grown and        consumed locally, reducing the need for importation of base fuel        and/or additives. Under such conditions an amount, or treat        rate, of up to 30%, or up to 40%, or up to 50% of the main fuel        composition is preferred, though concentrations of up to 60%        total additives including such fuel extender additives can be        considered particularly where the methanol source is crude        methanol.-   3. Combustion enhancers. These may also be referred to as combustion    improvers. An example of a combustion enhancer is a nitrated    ammonium compound, for example ammonium nitrate. At 200° C. ammonium    nitrate breaks down to nitrous oxide according to the following    reaction:

NH₄NO₃═N₂O+2H₂O

-   -   The nitrous oxide formed reacts with fuel in the presence of        water in a similar way to oxygen, eg

CH₃OH+H₂O=3H₂—FCO₂

H₂+N₂O═H₂O+N₂

CH₃OH+3N₂O=3N₂+CO₂+2H₂O

-   -   Other nitrated ammonium compounds that can be used include        ethylammonium nitrate and triethylammonium nitrate as examples,        though these nitrates may also be regarded as ignition enhancers        (cetane) rather than combustion enhancers as their main function        in the fuel is ignition enhancement.    -   Other combustion improvers can include metallic or ionic        species, the latter forming by dissociation under pre or post        combustion environments.

-   4. Oxygen absorbing oil. The oxygen absorbing oil is preferably one    that is soluble in water methanol mixtures. Oxygen absorbing oils    have low auto-ignition point and also have the ability to directly    absorb oxygen prior to combustion, in amounts of, for example, 30%    by weight of the oil. This rapid condensation of oxygen from a hot    gaseous phase into the oil/solid phase after evaporation of the    surrounding water will more rapidly heat the oil particle causing    ignition of the surrounding evaporated and superheated methanol. An    oil ideally suited to this role is linseed oil, in a concentration    of about 1-5% in the main fuel mixture. If this additive is utilised    in the main fuel composition, the fuel mixture should be stored    under an inert gas blanket to minimise decomposition of the oil by    oxygen. Linseed oil is a fatty acid-containing oil. Other fatty    acid-containing oils can be used instead of or in addition to    linseed oil. Preferred oils are those that dissolve in the methanol    phase or are miscible in methanol, to produce a homogeneous, single    phase composition. However, in some embodiments oils that are not    water/methanol miscible may be used, particularly if an    emulsification additive is also present in the fuel composition.

-   5. Lubricity additives. Examples of lubricity additives include    diethanolamine derivatives, fluorosurfactants, and fatty acid    esters, such as biofuels which are soluble to some extent in    water/methanol mixtures, on which the main fuel composition is    based.

-   6. Product colouration additives. Coloration additives assist to    ensure that the fuel composition could not be mistaken for a liquid    beverage such as water. Any water soluble colourant may be used,    such as a yellow, red, blue colourant or a combination of these    colourants. The colourant may be a standard accepted industry liquid    colourants.

-   7. Flame colour additives. Non-limiting examples include carbonates    or acetates of sodium, lithium, calcium or strontium. The flame    colour additives may be selected to achieve the preferred product    colour and stability in the final product pH. Engine deposition    considerations, if any, may be taken into account in selecting the    additive to be used.

-   8. Anti Corrosion additives. Non-limiting examples of anti-corrosion    additives include amines and ammonium derivatives.

-   9. Biocides. While biocides could be added, these are generally not    required because the high alcohol (methanol) content in the main    fuel prevents biological growth or biological contamination. Thus    according to some embodiments the main fuel is free of biocide.

-   10. Freeze Point depressant. While freeze point depressants can be    incorporated into the main fuel, the methanol (and optional    additives such as sugar, added for other purposes) depresses the    freezing point of water. Thus according to some embodiments the main    fuel is free of an additional dedicated freeze point depressant.

-   11. Deposit reductant. Non-limiting examples include polyolether and    triethanolamine.

-   12. Denaturant if required.

-   13. pH controlling agent. An agent that raises or lowers the pH to a    suitable pH can be used, which is compatible with the fuel.

The additives, and particularly those identified under items 1 and 2above may be added to the main fuel either as standard industry tradedproduct (i.e. in a refined form) or as semi processed aqueous solution(i.e. in a non-refined form, semi-refined form, or a crude form). Thelatter option potentially reduces the cost of the additive. A conditionof the use of such crude additive sources is that the impurities in thecrude forms of such additives, such as crude sugar solution, or sugarsyrup, as one example, do not adversely affect the fuel injectors orengine performance.

According to some embodiments, the main fuel comprises at least oneadditive. According to some embodiments, the main fuel comprises atleast two different additives.

Ethers are noted above as being examples of ignition improvers andsoluble fuel extender additives. Irrespective of the intended function,in some embodiments, the ether may be present in total at a level ofless than 20%, less than 15%, less than 10%, less than 5%, less than 3%,or less than 1% of the fuel composition. The amount may be greater than0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%. The lower andupper limits can be combined without limitation, provided the lowerlimit is below the upper limit selected.

In some embodiments, the main fuel composition comprises an ether in anamount of between 0.2% and 10% by weight of the main fuel composition.The ether is preferably a single ether or a combination of two ethers.

Through utilization of an ether as either an ignition improver and/orsoluble fuel extender, in a methanol-based fuel, a complete process forthe production, transport and utilization of a fuel composition has beendeveloped. The methanol-based fuel may be a water-free fuel or amethanol-water fuel in this instance. This is described in furtherdetail below.

Ignition Enhancer as Fumigant

The fumigant used in the method of embodiments of the invention relyingon fumigation comprises an ignition enhancer. The fumigant may furthercomprise other components, such as one or more of methanol, water andany of the additives outlined above in the context of the main fuel.

As described above, an ignition enhancer is a material that enhancesignition of a combustible material. One of the challenges to the use ofmethanol as the core fuel component in the main fuel composition for acompression ignition engine is the fact that methanol does not ignite asreadily as other fuels. An ignition enhancer is a material that has goodignition properties and can be used to create ignition, following whichthe methanol in the main fuel composition (and other combustiblematerials) will combust. The ignition characteristics of a potentialfuel component are described by the cetane number (or altenativelycetane index) of that component. The cetane number is a measure of amaterials ignition delay, being the time period between the start ofinjection and start of combustion, i.e. ignition, of the fuel. Suitableignition enhancers may have a cetane of above 40 (such as DME which hasa cetane of 55-57). The cetane number(s) of the ignition enhancer(s)present in the fumigant should be taken into account when determiningthe relative amounts of ignition enhancers to other components in thefumigant, and also the amount of fumigant compared to the main fuelcomposition, load and engine speed. The overall cetane of the fumigantwill be based on a combination of the proportional contribution of, andthe cetane property of each component, the relationship not necessarilybeing linear.

Some non limiting examples of ignition enhancers which can be includedin the fumigant include:

-   -   ethers, such as the lower alkyl (being the C1-C6 ethers),        notably dimethyl ether and diethyl ether,    -   alkyl nitrates,    -   alkyl peroxides,        and mixtures thereof.

Dimethyl ether is a preferred high ignition characteristic ignitionenhancer suitable for use in the fumigant. Diethyl ether is anotherexample of a suitable ignition enhancer.

Methanol in the main fuel can be catalytically converted into dimethylether. The dimethyl ether may therefore be catalytically generated froma stream of the main fuel composition, which is then fumigated into theengine separately to the main fuel composition (with the inlet air). Inthe alternative, a fumigant composition comprising dimethyl ether may beprovided by the fuel supplier to the engine owner as a ready-madefumigant composition. In another embodiment, a pre-fuel compositioncomprising methanol and up to 15% by weight of an ether ignitionenhancer (such as dimethyl ether), can be produced at one location andtransported (for example, through a pipeline) to another location foruse in fueling a compression ignition engine. In some embodiments, thepre-fuel may further comprise water. At the end of the pipeline, part orall of the ether ignition enhancer component in the pre-fuel can beseparated from the other components of the pre-fuel composition (notablythe methanol, but also other components having a higher boiling pointthan the ether). The separated ether component can then be fumigatedinto the compression ignition engine as a fumigant, separately to theremaining part of the pre-fuel composition, which is used as the mainfuel composition, either direct (particularly if it contains water), orwith further adjustment in composition (for example, to the watercontent) before use. The amount of ether ignition enhancer in thepre-fuel may be up to 10% by weight, or up to 9% by weight. The upperlimit will depend on the choice of ether and the temperature conditions.Further details are set out in the section below detailing CI enginepower generation systems.

The ignition enhancer, such as dimethyl ether, suitably comprises aminimum of 5% of the fumigant or a minimum of 10% of the fumigant, suchas a minimum 15%, 20%, 30%, 40%, 50%, 60%, 65%, 70%, 75%, 80%, 82%, 84%,86%, 88% or 90% of the fumigant. There is generally a preference for theignition enhancer content of the fumigant to be at the upper end of therange, so in some embodiments the ignition enhancer content is above 70%or more. The ignition enhancer may comprise up to 100% of the fumigant,for example, in the case of introducing a pure component from storage orfrom recovered separated ignition enhancer sourced from a pre-fuelcomposition. When converted from the main fuel through catalyticreaction of the main fuel (which comprises components in addition to themethanol, from which the DME is formed) or if impure high ignitioncharacteristic component is produced or drawn from storage, the upperlimit for such component will be reduced accordingly.

The relative amounts of each component in the fumigant may be keptconstant, or may be varied over the time period of operation of theengine. Factors that impact on the relative amounts of components in thefumigant include engine speed (rpm), level and variability of load,engine configuration, and the specific properties of the individualcomponents of the fumigant. In other embodiments, the fumigantcomposition may be kept relatively constant, and instead the relativeamount of fumigant (grams per second fumigated into the engine) comparedto the main fuel composition injected into the engine (grams per second)is adjusted during the different stages of operation of the engine.

When it is desired to operate the CI engine with different fumigantcompositions for different engine operation conditions (speed, load,configuration), the fumigant composition can be varied to suit bycomputer control of the fumigant composition, or by any other form ofcontrol. The adjustments may be sliding adjustments based on analgorithm that calculates the desired fumigant composition to match theprevailing engine operation conditions, or may be step-wise adjustments.For example, a higher overall cetane index fumigant (such as 100% DME)could be fumigated into the engine at a high weight % with respect tothe fuel for operation in some conditions, and then the fumigant couldbe switched to a second composition containing a lower % of DME and somelower cetane index components. In another embodiment the composition maybe stable and the air/fumigant ratio varied.

The target % of non-water components other than the ignition enhancer orenhancers in the fumigant is suitably not more than 40%, such as between5-40% or 10-40% or 20-40% 30-40%. Adjustments may be made to thesepercentages based on the cetane number of other ignition enhancers andcombustible components, and specific engine configuration. Additionallyin some embodiments water may be present in the fumigant either asproduct of a conversion reaction (eg methanol to DME) or as a carrythrough from a water containing reactor feed, or added in a separatestream.

Examples of components that may be present in the fumigant in additionto the ignition enhancer include methanol, water, the additives outlinedabove, and alkane gases (typically straight-chained alkanes, includinglower alkanes such as the C1-C6 alkanes, notably methane, ethane,propane or butane, and longer chain alkanes (C6 and above).

In some embodiments, the fumigant comprises at least 60% of a singlecomponent, one example being dimethyl ether. The amount of the singlemain component of the fumigant may be above 62%, 65%, 68%, 70%, 72%,75%, 78% or 80%.

The fumigant, or secondary fuel, may be obtained in a pure form directlyfrom storage, or may be supplied as a fumigant to the engine in a pureform after processing the main fuel (though catalytic conversion ofmethanol to DME, followed by purification to yield a fumigant consistingof DME). Alternatively, the fumigant may comprise an ignition enhancerand other components (i.e. the fumigant is not in pure form) afterprocessing the main fuel or from storage. In this case the impuritiesare still compatible with the desired outcome of fumigation i.e. thefumigant may also include water and methanol, or may contain othermaterials (such as C1-C8 alcohols) which are compatible with theapplication.

The main fuel composition and the fumigant may be supplied as a two-partfuel, or may be delivered as a “kit” of two fuel parts. In this context,the fumigant may be described as a “secondary fuel component” of thetwo-part fuel, and thus the description of the fumigant above alsoapplies to the second fuel component. The main fuel composition and thesecondary fuel component may be pumped into separate storage tanksassociated with the compression ignition engine.

Thus, according to one embodiment, there is provided a two-part fuel foruse in operating a compression ignition engine, the fuel compositioncomprising:

-   -   a main fuel composition comprising methanol and water and    -   a secondary fuel component comprising an ignition enhancer.

In the use of this two-part fuel, the main fuel is introduced into thecombustion chamber of the compression ignition engine, and the secondaryfuel is fumigated into the air intake of the compression ignitionengine.

According to another embodiment, there is provided a method forsupplying fuel to a compression ignition engine, the method comprising:

-   -   supplying a main fuel composition comprising methanol and water        to a first tank that is in fluid connection to a combustion        chamber of the compression ignition engine, and    -   supplying a secondary fuel component comprising an ignition        enhancer to a second tank that is in fluid connection to an air        intake of the compression ignition engine.

As described above, the secondary fuel may be prepared fully orpartially in situ through catalytic conversion of a portion of the mainfuel into the ignition enhancer. This is particularly suited tosituations where dimethyl ether is the ignition enhancer.

The present invention also provides for the use of a two-part fuel inthe operation of a combustion ignition engine, wherein the two-part fuelcomprises:

-   -   a main fuel composition comprising methanol and water, and    -   a secondary fuel component comprising an ignition enhancer.

The present invention further provides a pre-fuel composition comprisingmethanol and up to 10% by weight of an ether. The ether may be dimethylether. In some embodiments, the pre-fuel may further comprise water. Asnoted above, the ether component can be separated from the remainder ofthe pre-fuel composition for use as the secondary fuel component, andthe balance of the pre-fuel composition can be used as the main fuelcomposition. This balance may be used direct as the entire main fuelcomposition (particularly if it contains water), or the composition canbe adjusted to yield the main fuel composition, for example, throughaddition of water. In this embodiment, therefore, the pre-fuel might notcontain water, and water can be added to generate the main fuelcomposition after removal of the ether. In some embodiments, water maynot be required for use in the main fuel composition, when the fuel isused in one of the power generation systems described further below.

The present invention also provides a method of transporting a two-partfuel composition comprising methanol on the first part, and an ether onthe second part, from one location to another location, comprisingtransporting a pre-fuel composition comprising methanol and ether fromone location to a second location, and separating the ether from themethanol to yield a first fuel part comprising methanol, and a secondfuel part comprising ether. The transporting may be by way of pipingthrough a pipeline. The first location may be a methanol productionplant location, and the other location (the second location) is alocation remote from the first location. The remote location wouldtypically be at least 1 kilometer away, and perhaps many kilometersaway. The remote location may be the location of a compression ignitionengine for electricity generation, or a shipping port, or a train sidingor any other suitable location where the two-part fuel is required.

Engine Operation Details

FIG. 1 illustrates a flow chart outlining the process of using a mainfuel 11 of methanol/water mix in a CI engine 10. The process includesfumigating an intake air stream 12 with an ignition enhancer 14 and thenintroducing the fumigated air, through an ignition control 30, into thecombustion chamber of the engine 10 before introducing the main fuel 11into the combustion chamber and igniting the main fuel/fumigated airmixture by compression ignition in order to drive the engine.

The intake air 12 is fumigated with a fumigant 17 comprising theignition enhancer 14. The fumigated intake air 12 is then injected intothe combustion chamber before or during the initial stage of thecompression stroke of the engine so as to compress the air before themain fuel is injected into the combustion chamber. Compression of theair raises the temperature in the combustion chamber to providefavorable ignition conditions for the main fuel when it is sprayed intothe chamber during the last stage of compression.

Fumigating the intake air 12 with an ignition enhancer 14 encourages afurther increase in temperature of the compressing air making it evenmore combustible at the point of fuel injection due to pre-combustion offumigating material, and the presence of breakdown species which aidsthe onset of combustion of methanol.

Fumigation as described above allows pre-combustion to occur in thecombustion chamber prior to fuel injection. This two step ignitionprocess, or ‘kindled’ operation, relies on the compression stroke of theengine piston to raise the temperature of the fumigated air to the pointof ignition. In turn, this enhances the ignition conditions in thecombustion chamber to provide a sufficiently hot environment for themethanol and water fuel, when injected towards the end of thecompression stroke, to undergo accelerated ignition under increasedtemperature conditions, rapidly vaporizing the methanol and evaporatingthe water in the fuel and producing high thermal efficiency.

The temperature contribution by fumigant for stable engine operation atlow water levels is 50 to 100° C. At the point of main fuel injectionfor low water level fuels this contribution results in a combustionchamber temperature comparable to the temperature in known combustionignition engines. As water levels increase in the fuel the amount offumigant may be adjusted to offset the cooling effect of the water. Theresultant brake thermal efficiencies are comparable to those of dieselfuels, with net efficiency outcomes being dependent on various factorssuch as the size of the engine and its configuration.

Efficient and complete combustion of the methanol and water fuel in thismanner minimizes un-burnt or modified hydrocarbons and particulates inthe exhaust emissions resulting in cleaner emissions. This isparticularly evident in larger CI engines with slower speeds where theefficiency of the combustion process is maximized because sufficienttime is allowed for the commencement and completion of the two steps ina kindled operation.

The term “fumigation” in relation to the intake air refers to theintroduction of a material or mixture, in this case a fumigantcomprising an ignition enhancer, into the intake air stream to form avapor or gas through which the ignition enhancer is well distributed. Insome embodiments the material is introduced in a small amount, generallythrough spraying a fine spray of the material into the intake air streamor injected as a gas.

The kindled operation has the effect of pre-heating the intake airduring the compression stroke. The nature of a water methanol mixture isthat less sensible heat is generated in the reaction products aftercombustion, heat being required to evaporate the water present. Thismeans that compared to a diesel engine operating on hydrocarbon fuelsmore severe engine conditions can be accommodated at the point ofinjection while keeping within the engine's design limitations. Thesemore severe conditions arise through fumigant combustion or increasedair temperature (through directly heating the air) and/or increasedpressure and temperature through the use of modified engineconfigurations, such as turbocharging or supercharging.

The amount of ignition enhancer(s) may be controlled relative to the mixof methanol to water contained in the main fuel in order to produceconditions within the combustion chamber where ignition of the main fuelis achieved in a timely manner, and thereby deliver the best possiblethermal efficiency from the engine. Where the ratio of ignition enhancerto fuel mix is not controlled combustion could initiate significantlybefore TDC, such as 25-30° before TDC, and as such the use of anignition enhancer could have a neutral effect and make a minimal or nocontribution to the thermal efficiency of the engine. In a preferredoperation of the engine ignition of the fumigant/air mixture is timed todelay the combustion of this fuel as late as possible (to avoidunnecessarily working against the power stroke of the engine) and to beconsistent with good combustion of the main fuel after injection. Thismeans that the secondary fuel should ignite before the main fuelinjection commences, but not so much before that the energy contained inthe secondary fuel makes a minimal or nil contribution to the thermalefficiency of the engine.

Ignition of the main fuel can be controlled, at the ignition control 30illustrated in FIG. 1, to be as close as possible to the ideal timing byusing one or a combination of the following ratio ignition controls:

-   1. Controlling the amount of fumigant introduced into the air intake    relative to the main fuel.-   2. Controlling the percentages of ignition enhancer(s) to other    components in the fumigant (recognizing that water and other    components such as methanol may also be present).-   3. Controlling 1 and 2 above, depending on engine operating at high    loads (50% to 100%) or low loads (below 50%) across the rpm    operating range of the engine.

Although the relative amounts of fumigant to main fuel introduced intothe engine (either through the air intake, or into the combustionchamber, respectively), will vary depending on the engine operationconditions that apply, it is generally desired for the amount ofignition enhancer in the fumigant during steady state operation at midor high load to be a relatively low percentage by weight of the mainfuel composition. For a fumigant comprising 100% ignition enhancer (suchas DME), the relative amounts of fumigant to main fuel by weight isdesirably up to 20% by weight, up to 18%, up to 15%, up to 13%, up to10%, up to 8%, up to 7%, up to 6%, up to 5%. The fumigant level ispreferably at least 0.2%, at least 0.5%, at least 1% or at least 2% byweight of the main fuel composition. These figures are based on weight,assuming the fumigant comprises 100% ignition enhancer, and can beadjusted proportionally for a reduced ignition enhancer content in thefumigant by weight. These may be measured by reference to the amountintroduced into the engine in grams per second, or any other suitablecorresponding measure for the engine size. An upper limit of around 10%or less (such as 8% or 7%) is additionally advantageous, as a pre-fuelcomposition containing up to the required amount of ether as ignitionenhancer (such as 10%, 8% or 7% ignition enhancer, respectively) can bedelivered to the compression ignition engine location, and the ignitionenhancer flashed off and recovered in a quantity corresponding to theneeds of the engine operating with fumigation at the same target level.In other embodiments, there can be top-up of the fumigant level to ahigher level at the engine location (for example, through top-up fromseparate storage of ignition enhancer, such as ether).

Ignition control 30 controls the above ratios to control the nature ofthe intake air entering the engine 10. Specifically, and with referenceto FIG. 1, ignition control 30 controls the amount and relativeproportions of air 12, fumigant 17 including concentration of ignitionenhancer 14 in the fumigant 17, and other components 19 in the fumigant17.

In relation to paragraph 2 above, the target % of non-water componentsother than the ignition enhancer in the total fumigant/air flow may benot more than 40%, such as between 5-40% or 10-40% 20-40% or 30-40%,with the balance being ignition enhancer, for example, DME (which has acetane of 55-57). Adjustments may be made to these percentages based onthe cetane number of other ignition enhancers and specific engineconfiguration. All percentages are by weight. Water may be present inany amount consistent with smooth operation of the engine, such watermay arise from the fumigant, for example if made catalytically from thefuel, or as part of the ambient air inlet flow to the engine, or may beadded by other means.

FIG. 1 illustrates a portion 13 of the main fuel 11 being diverted awayfrom the engine 11 and toward a catalytic reactor 20 in which thecatalytic dehydration of methanol to DME is effected. The DME producedis used as an ignition enhancer in fumigant 17 for fumigating the intakeair 12. Other embodiments described herein utilize other techniques forgenerating the dimethyl ether, when used as the ignition enhancer of thefumigant. In some such embodiments, the DME may be generated at thelocation of methanol generation, and delivered as a part of a pre-fuelcomposition to the engine site.

The catalytic reactor 20 operates under standard industry conditions asare known by those practiced in the art in order to effect dehydrationof the methanol in the methanol/water fuel. As illustrated in FIG. 1 thesource of heat for operating the catalytic reactor 20 is the exhaust gas22 from the engine 10 which transfers through a heat exchanger (notshown) to heat the diverted part of the main fuel in the catalyticreactor 20. Exhaust gas temperatures can range between 200° C. to over500° C. and are usually dependent on the load of the engine, namely ahigher engine load will produce higher exhaust temperatures.

FIG. 1 shows that after harnessing the heat from exhaust gases or otherheat sources as required to power the catalytic reactor the engineexhaust gas 22 is cooled after transferring through the heat exchangerin the catalytic reactor, exhausts to atmosphere 28. Alternatively, oradditionally, as illustrated in FIG. 1, the exhaust gas can be treatedwith a portion condensed and recycled back to the main fuel as recycledfuel 32 that has been treated through a condenser 25, (where any coolingmedium may be used) that in the embodiment illustrated includes a saltwater/water heat sink 34 (heat exchanger), which is suitable for use onships. Additional exhaust treatment steps utilising condensate or othermeans can be also be taken to reduce targeted pollutants to low levelsin the exhaust gas to atmosphere (28). In another embodiment componentssuch as any unburnt fuel can be adsorbed onto an active surface andlater desorbed using standard techniques, and included as main fuel orfumigant component to further reduce pollution. Alternatively a catalystcan be employed to catalytically react any oxidisable species such asunburnt fuel, increasing the exhaust temperature and providing anadditional source of heat which may be utilized.

Additionally, if multiple engines are operating, for example to produceelectricity, the aggregated exhaust gas can treated as a single streamto be treated/condensed with the recycle fuel from the exhaust beingdirected to one or more of such engines.

A second fuel storage 38 provides fuel for either direct use as asecondary fuel, namely the fuel is a fumigant comprising an ignitionenhancer, or for conversion into a secondary fuel through the catalyticreactor 20. The fuel in the second fuel storage 38 may be used as analternative to obtaining a portion 13 of the main fuel 11 for conversionthrough the catalytic reactor 20, or may be used in combination with theportion 13 of main fuel.

The poor cetane characteristic of methanol/water fuel, particularlythose having a medium to high water level, can also be offset bypreheating either the main fuel and/or the intake air. Preheating can beachieved by a variety of techniques including any one or a combinationof the following:

-   1. Waste heat Pre-heater—Using the CI engine exhaust, or other waste    heat, to preheat the intake air and/or main fuel through heat    exchange. A fan may be introduced to optimise the pressure profile    of intake air through the engine cycle.-   2. Supercharger/blower—or other air compressing means driven by the    engine to force induction of intake air into the combustion chamber,    and heating intake air through increase in air pressure.-   3. Turbocharger—or other air compressing mechanism driven by engine    exhaust or other waste heat to force induction of intake air into    combustion chamber, and heating intake air through increase in air    pressure.-   4. Using direct methods to heat the air, such as electrically    heating via elements or combustion of fuel to generate the required    temperature increase. Such methods may be useful during startup and    at low engine loads.-   5. Glowplugs (or hot bulbs)—directing heat into the engine    cylinders.

Option 1 (without a fan) above would result in a lower power output fromthe engine due to a lower mass flow of air (compared to options 2 to 3where the mass flow of air is not reduced), however this loss of maximumpower may be offset in part by a higher efficiency in combustion in thehotter conditions at the point of fuel injection and a lower requirementof excess air compared to petroleum based diesel fuels. A compensatingpressure fan can offset the reduced mass flow of air under conditions ofincreased air temperature.

The temperature required at the point of fuel injection and thereforethe level of preheat required to ignite a water/methanol mixture dependson the amount of water present. At low to medium water level, andsubject to specific formulation this can be achieved by an air preheattemperature of 50-150° C. However, with a medium to high water level,eg. a 50%/50% water/methanol mixture, an air preheat of 150-300° C. canbe used.

In another embodiment heating of the main fuel according to knowntechniques can assist the ignition process.

The preheat option in combination with a medium to high water lowmethanol fuel alters the engine cycle from being a constant volume cycleduring the ignition and combustion and initial expansion phase, todirectionally more of a constant temperature expansion (where the heatfrom the methanol is in significant part evaporating water) in atimeframe most suitable to maximise engine performance.

Some adjustment to the fuel and process described above may be requiredto optimise operation and efficiency in smaller CI engines operating athigher engine speeds, for example at 1000 to 3000 rpm, and above. Inaddition to fumigating the air intake stream with a fumigant comprisingan ignition enhancer, the following operational aspects may be usedseparately or in combination for engines operating at higher speeds:

-   -   pre-heating air intake as described above including by direct        heating (from an independent heat source), heat exchange with        exhaust gases, supercharger or turbocharger.    -   heating the combustion chamber using, for example, glowplugs.    -   pre-heating main fuel intake.    -   adding additives to the main and/or secondary fuels that improve        ignition and combustion of the fuels. Some of these additives        are discussed above.    -   selecting the appropriate water level in the main fuel        composition as discussed above, such as a low to medium water        level range.    -   selecting the water level in fumigant to a suitable level        consistent with the engine configuration.

These options can additionally be utilized if desired when operating alarger CI engine at lower engine speeds, such as 1000 rpm or less.

CI Engine Power Generation Systems

Using the methanol/water mix fuels described herein and the relatedsystems (also referred to as processes) for powering a compressionignition engine, power generation systems and structures can bedeveloped to efficiently generate power at reduced emission levels, andwhich can also treat the engine exhaust to capture and then re-use orre-direct heat and water from exhaust gases. The re-use, or recycling,of heat and water promotes increased system efficiencies and overallreduced waste products and emissions. The re-direction of heat and watercan find use in a range of unrelated applications involving heating andcooling localities/quarters and the regeneration of water for use bycommunities or as part of other systems.

FIGS. 3A to 6B illustrate examples of power generation systemsincorporating the processes and fuels described herein for powering acompression ignition engine. It is understood that the fuel representedin these processes is a methanol based fuel that may contain variousamounts of water, and may contain water in the amount of 0% to 80%.

FIGS. 3A and 3B show a process for producing and supplying a methanolfuel to an IC engine 111 (also referred to as a diesel engine) toproduce output power but to also include an engine exhaust treatmentthat reduces emissions, that harnesses engine exhaust to recycle waterand that also incorporates a Hot Water Loop (HWL) 113 a, 113 b (seeFIGS. 4A and 4B) to provide heat to a local community. Output powerproduced by the engine can also be used to service the locality in whichthe power generating plant is located, and for example can be used togenerate electricity for a community. FIGS. 3A and 3B differ in thatFIG. 3A shows the process utilizing air fumigation into the engine,while the process shown in FIG. 3B omits the step of fumigating inletair.

FIGS. 3A and 3B illustrate a fuel manufacturing plant 101 and the remotesupply of that fuel through a supply grid 103. The fuel manufacturingplant may be a conventional methanol manufacturing plant usingelectricity generated from steam produced from conventional boilers inlarge remote coal plant 102. Such a plant produces a coal firedemissions profile. Alternatively, the electricity generating plant 102could incorporate a combustion engine using a methanol fuel as describedherein to generate the electricity required to produce the methanolfuel. This would provide a cleaner alternative with lower emissions tothose produced by a coal plant.

Methanol based fuel is manufactured in plant 101 and may largely containmethanol, a methanol-water mix or a methanol-ether mix or amethanol-water-ether mix. In one embodiment the fuel comprises a “WholeFuel” Methanol and DME mixture in a 90-99.5% blend of methanol and DMEas a non-boiling liquid at atmospheric pressure which may be useddirectly with the engine 111. In the mix of methanol and DME the DME isprovided in a stable quantity suitable for transmission as a liquid andto avoid transition of the ether into the gas phase. The quantity willdepend on the pressure and temperature at which the fuel is transmittedin the pipelines 103, but will generally be less than 10% of the totalfuel amount, and in the range of 7%-8%.

Alternatively fuel having a higher DME proportion under pressurisedconditions may be supplied. In another alternative, a fuel containing ahigh methanol content approaching 100% methanol (eg. chemical grade)could be transmitted for subsequent part conversion to DME near thedemand centre (namely the power generation plant). This form of pre-fuelcomposition comprising a high % of methanol may contain a watercomponent of around 0.2% or more. In a further alternative, the fuel orpre-fuel transmitted in the pipelines may be a methanol-water fuel. Thewater in the methanol-water fuel can either be associated with themethanol, such as in crude methanol, or may be sourced from a surplus ofwater in the manufacturing area that may be cost effectively used forthis purpose. Some additive addition of lubricity and corrosion improvermay be included in the transmitted fuel depending on the materials ofconstruction in the transmission grid and to enhance engine/processoperation

Transmission of large amounts of energy in flammable liquids over longdistances in pipelines in regional grids is established technology. Suchinfrastructure as pipelines 103 can be also used to deliver the methanolfuel to distant locations safely and cost effectively.

After being transmitted through pipelines 103 the fuel arrives at apower generating plant including the compression ignition engine 111, apre-processing stage 104 and exhaust treatment 113, 115, 116 118. Thefuel may be used in the engine 111 immediately as is, or optionalpre-treatment of the fuel may be carried out to ensure safe and reliableoperation through the plant operating range. Storage of a start-up andshutdown fuel can also be contemplated for system integrity reasons, forexample, an ether component could be stored.

At the pre-processing stage 104 the fuel may be split by flashing intotwo rich phases, one a methanol rich 107 and one an ether rich part 105,such as DME. DME is particularly suited to this flashing process due toits low boiling point. Low level waste heat from engine exhaust from ahot water stream having a temperature of 50° C.-60° C. can be used toflash separate low boiling point DME from methanol. In some embodimentsthe methanol rich phase may include low amounts of DME, with most DMEbeing flashed off. In other embodiments a high proportion of DME may beretained in the liquid phase with only sufficient DME to ensure good andcomplete combustion being vaporised and utilised as fumigant 105. Forexample if the fuel from the manufacturing plant includes 7% DME, 5% ofthis may be retained in the liquid phase with 2% being used as fumigant105 for adding to heated combustion air 110 entering engine 111.

Pre-processing may include a conversion option to supplement the supplyof DME or other fumigant. Alternatively, the required quantity ofignition improving agent, such as DME, may be obtained from storage.Other such agents are also possible such as DEE and other ignitionimprovers described herein.

The pre-processing stage may also include processing part of thetransmitted fuel to not only separate DME to be used as a fumigant butalso to produce excess DME for use as liquid fuel ingredient for otherprocesses. For example, surplus DME could benefit a nearby community byproviding surplus heat to the HWL. Alternatively or additionally, theDME could be integrated with generator plant processes. Methanol fuel,whether before or after processing, could also be removed from the powergenerating system and used for local chemical manufacture

Transmission to the generating plant of crude methanol is also possible,saving capex and opex costs in an upstream manufacturing plant. Such afuel feed to the power generating plant would suit the option above ofsplitting out part of the crude methanol for DME production, with theremaining fuel being directed into the engine. In terms of energy andcapex, this option would replace a distillation unit at themanufacturing plant 101 with most product being distilled and going“over the top” by a much smaller unit at the power generating plant witha relatively low amount going “over the top”. This option would alsomake available local DME near demand centres, and namely near the powergenerating plant.

The pre-treatment of fuel at the pre-processing stage 104 can also heatthe methanol fuel 107 prior to entry into the engine, with cool water,derived from the venturi scrubber 115 return line exiting thepre-processing stage 104 as irrigation-quality water 106. Cooledirrigation-quality water 106 may mix with condensate from condenser 116,and if necessary a cooler could be used to ensure acceptable effluenttemperature.

In the example shown for power generation with a HWL, the diesel enginewould be used generating power from 1 MW and above. This does notexclude power below 1 MW which could serve smaller users and have a lowNOX, SOX and particulate outcome. A diesel engine is particularly suitedto post combustion treatment because it provides the driving force ofair pressure needed to move exhaust through cleanup and heat exchangeequipment at only a small cost on engine efficiency.

The nature of some of the fuel mixtures described herein means thatlarge diameter pistons are preferred over smaller pistons due toinherent thermal benefits at engine size being increased. Larger pistonsalso reduce the risk of impact of injected fuel on the piston walls,ensuring the fuel combusts properly and does not interfere with thelubricant film.

While the experiments mentioned further below demonstrate fuel tested inan engine running above 1000 rpm, as previously suggested the fuel canbe successfully used in slower speed engines, normally operating at justbelow 100 rpm up to 1000 rpm, which is the range normally described asbeing the low to medium speed range. This speed range allows more timefor volatile ignition improvers to get into the vapour space as vapourand commence their chemical reactions with the hot compressed air duringthe compression stroke. This greater time allowance during thecombustion phase will allow more complete combustion of fuel and reducethe level of unburnt fuel and other components in the engine-outexhaust. The greater time allowance will also allow for more time tocompletely combust the fuel in the cylinder through the contact of waterand oxygen molecules, allowing lower lambda to be used and in so doingincreasing the concentration of water in the engine out exhaust.

Power is generated at engine 111 by a mixture of methanol 107 and water108 entering engine 111 together with air 100, which can be pre-heatedand in the example shown in FIGS. 3A and 3B is pre-heated by engineexhaust gases through a condenser 116. A suitable pre-heated temperaturecould be between 40° C. and 50° C. Water in the fuel may be sourced froma water storage or from water recycled from exhaust gas throughcondenser 116 (explained in more detail below).

Treatment of exhaust gas includes passing engine exhaust through acatalytic converter 112 using catalysts targeting CO2 and oxygenatedcompounds. This will cause marginal heating of the exhaust gas wherethat heat may be available for the HWL, or for other processes describedfurther below in relation to FIGS. 5A, 5B, 6A and 6B. The catalyticconverter 112 also reduces any fuel or combustion products to anappropriate level. A final stage activated carbon or similar canoptionally be employed to clean up. Additionally, the methanol fueldescribed herein burns clean with low soot, which improves catalystperformance.

The HWL carries heat to a local-based destination such as a residentialcommunity through a loop of pumped water. FIGS. 4A and 4B illustrate theHWL supply line 113 a and return line 113 b at the HWL heat exchanger113. Harnessing heat by-product from the power generation process can beused to provide low cost heating to residential and commercial quarters.The water pumped through the HWL is heated through a HWL heat exchanger113 downstream from the catalytic converter 112. The heat exchanger 113is a standard unit operating at temperatures on return of the HWL of 40°C. with a design dispatch temperature of 80° C. to the HWL. Therelatively cool HWL return temperature and efficient exchanger design interms of required surface area will ensure sufficient cool down of theexhaust.

Exhaust treatment additives are added at caustic injector 114, whichinjects any caustic chemicals, and other suitable acid neutralisingagents, into the exhaust gas for a desired outcome. For example, toeliminate acidic compounds from the final exhaust a low dose of a basicliquid (eg 50% caustic soda and water) will be injected into the exhauststream, used to nullify trace acids and control the pH of the irrigationwater flowing from the plant. Final pH will be controlled to a levelthat best meets local conditions.

A venturi scrubber 115, or other suitable mixing device, is illustrateddownstream of the HWL exchanger 113. This unit has several functions,the first being to intimately mix the exhaust gases with a circulatingwater flow, the effect of the water flow being to cool down the exhaustfrom 85-90° C. out of the HWL exchanger to approximately 55-60° C. outof the venturi scrubber. Such cool down will create condensed water fromthe exhaust gas and collect particulates that can be treated using knownmethods, or ultimately form part of the final irrigation water leavingthe plant for return to the ground. The de-acidified and clean exhaustleaving the scrubber 115 produces a higher purity exhaust out of thefinal condenser.

Water is pumped between the venturi scrubber 115 and a fin fan heatexchanger 100. The fin fan heat exchanger, or other suitable equipment,is another gas/liquid exchange that takes the heat from exhaust gasthrough the venturi scrubber and rejects that heat to air, which isdriven to flow through the heat exchanger 100 by one or more fans. Oneadvantage of heat rejection in this manner is that the heat is rejectedat low temperature, and therefore does not have a large impact on theoverall efficiency of the process.

Alternative to expelling heat to atmosphere, heated air from the fin fanexhaust may be used directly into the engine as heated combustion air110, in which case some pressure may be applied from the fan to offsetthe heating effect on mass flow of air. Another alternative to expellingheat to atmosphere is to dissipate heat through a cooling pond or otherwater system capable of dissipating a large amount of heat in aresponsible and environmentally acceptable way.

FIG. 4A illustrates a final large exhaust gas/combustion air exchanger,namely condenser 116 that recovers water in high water recovery systems.In systems where high water recovery is not necessary, condenser 116 isnot included. FIG. 4B illustrates a medium water recovery system similarto that of FIG. 4A but with the omission of condenser 116.

The final (optional) condenser 116 cools the exhaust from the venturiscrubber 115 down from approximately 50-60° C. to within about 5-20° C.of ambient temperature. In lowering the temperature by this amount thewater produced recovered from the plant is significantly increased. Inaddition to producing water for irrigation, or re-use outside the powergeneration plant, the condensate from the condenser 116 may optionallybe useful within the power generation process.

Condensate may be injected in with the pre-processed fuel to reduce NOXformation and associated acidity issues in the downstream equipment,such as in the HWL exchanger. The condensate may also form a source ofwater to be used in the combustion of particular fuel blends as analternative or in addition to stored water. Furthermore, the highergrade water from the condenser may be further treated into potablewater, or may be added to the irrigation quality water produced by theventuri scrubber and to re-circulate between the venturi scrubber 115and fin fan heat exchanger 100.

The heat from cooling the exhaust is not wasted, but can be exchangedwith inlet air into the engine 111. Aside from the benefit thatrecycling waste heat and water makes to the fuel required and emissionsproduced in the process, recovery of water and heat tends to alsostabilise engine operation. Colder inlet air to the engine allows moreheat to be recovered.

FIG. 3B differs from FIG. 3A in that it illustrates the process forproducing and supplying a methanol fuel to engine 111 without fumigatingintake air with an ignition improver.

Methanol fuel from the manufacturing plant 101 is transported throughthe pipeline infrastructure 103 for direct use with the engine 111,where the intake air 110 is pre-heated. Pre-processing to flash separatean ether from the transported fuel is not required as fumigant is notrequired. Pre-processing may still however take place to prepare thefuel for combustion and/or to separate ethers for separate use outsidethe power generation plant. It is also understood that in relation toFIG. 3A, the step of pre-heating the intake air with exhaust heat is notessential and could be omitted. It is however useful to make use ofexhaust heat and recycle exhaust particles to improve engine efficiencyand reduce emissions. Alternatively the water from the venturi scrubberto the fin fan could in principle be used for the purpose of heating theinlet air.

In the process illustrated in FIG. 3B, intake air can be preheated byvarious means including using the heat transferred from exhaust gas, forexample through condenser 116 or from heat taken from exhaust earlier inthe post-combustion process such as at the catalytic conversion stage.Alternatively, intake air is pre-heated using other techniques describedherein including direct heating with electrical heating elements, glowplugs, and indirect heating such as by way of superchargers orturbochargers.

FIGS. 5A and 5B illustrate how the concept of the power generation usingthe technology and fuel described herein can be applied to power a railvehicle. Reference numbers in FIGS. 5A and 5B correspond to the samenumbers and items used in relation to FIGS. 3A and 3B. Anypre-processing 104 of the fuel and the use of the fuel through theengine 111 is the same. Exhaust air is cooled after exiting thecatalytic converter 112 through a first heat exchanger 120 that usesambient air to cool exhaust and heat combustion air 110.

The exhaust treatment on a rail vehicle differs from that of the HWLprocess in separating water from other exhaust material. Exhaust gasexiting the catalytic converter is passed through an activated Aluminawater adsorbing cycle 121 and an activated Alumina water evolving cycle122 to produce clean hot and dry exhaust to atmosphere with therecapture of water from exhaust gas through a water condenser 123.Recaptured water can be supplied back into the pre-process stage or usedfor non-potable rail vehicle use. The cooler dry exhaust exiting theactivated alumina cycles can be used through a second heat exchanger 124to provide heating or cooling on the rail vehicle.

The manufacture of fuel at the methanol plant 101 would lead in oneembodiment to potentially two components being stored on the railvehicle: (1) a water methanol mix designed to provide the correctNOX/performance outcome, and (2) a fumigant component in separatepressurised storage. Rail weight penalties are not large comapred toshipping weight penalties.

FIG. 5B, similar to FIG. 3B, illustrates the rail vehicle powergeneration process without the use of fumigant, and relying only onpre-heating. The same comments on the merit of the HWL process withoutfumigant apply for the process described in relation to FIG. 5B.

FIGS. 6A and 6B illustrate the concept of the power generation processused for marine purposes, and for example on a ship. Similar to the HWLpower generation process example, a methanol manufacturing plant sizedfor a ship can be provided on the ship in order to supply methanol basedfuel to one or more engines 111 that power the ship. Similar to theexamples above, FIG. 6A illustrates a process using fumigant ignitionenhancer in the intake air while FIG. 6B illustrates the process withoutfumigant. The process could instead include no pre-heat or pre-heat ofintake air.

A first heat exchanger 120 on the marine vehicle cools exhaust air usingcooler ambient air. A portion of that exhaust air can be re-circulatedback to become heated combustion air 110. The remaining cooled exhaustair is then passed on to a desalinator 125 and other heat exchangeequipment in order to maximise exhaust heat recovery for the vehicle'sneeds such as tank and vehicle heating. The desalinator makes use ofseawater readily available to marine vehicles

The general advantage associated with the processes and fuels describedherein when used in the applications described above is that it enablesthe simultaneous delivery of several benefits to energy and resourceconstrained communities and quarters. Specific advantages include:

-   -   Development of remote resources that may otherwise remain        undeveloped due to unsuitability (eg high sulphur).    -   Provide seamless options for efficient biomass co-processing to        reduce CO2.    -   Earliest co-use of biomass would extend the life of existing        resources.    -   The integration of other renewable is also a possibility, such        as wind and sun    -   Provide electricity to demand centres on a combined heat and        power (CHP) or combined cooling heat and power (CCHP) basis.    -   To virtually eliminate all non-CO2 pollutants arising from the        production stage of electric power.    -   To capture hydrogen from resources to the maximum extent        possible and convert these resources to water for use by demand        centres (1 part hydrogen converts in reaction with oxygen to 9        parts of water by weight). Under such arrangements a fossil fuel        resource can also be regarded in part as a water resource with        potential “free carry” effect, as the fuel delivery mechanism        will in any case absorb its own distribution costs. This water        will be treated with activated alumina or other suitable        adsorption material or technology to remove breakthroughs which        pass the catalytic converter which treats the hot engine        exhaust.    -   Provide waste heat to local communities by a hot water loop        (HWL) cooling down the exhaust and exchanging this major source        of heat energy with local demand centres for heat, for heating        or refrigeration purposes. The clean exhaust from utilising the        technology described herein allows proximity of power generation        to market, a feature not normally available to coal fired power        generation in particular.    -   Efficiently recovering water and heat. Other heat transfer        approaches can be used, with increased recovery though at higher        cost, and combustion air can also optionally be heated by, for        example, the circulating water prior to the fin fan cooler (in        the example of FIGS. 3A and 3B).    -   High recovery of water may be obtained, in the vicinity of 0.7        to 1 tonne irrigation water per tonne of methanol consumed, or        higher if justifiable on economic and engineering grounds.    -   Provide pH neutral irrigation water for direct use by local        communities    -   Provide a water washed exhaust which neutralises acids and        removes particulates down to low levels. Other pollutants such        as SOX and hydrocarbons in the exhaust will also be low.

The technology described herein with water production, HWL heatintegration and emissions outcomes will come at a cost in terms ofengine efficiency, however this aspect is in many cases expected beoffset by supply chain benefits and the benefits mentioned above.

EXAMPLES Example 1 Experimental Program to Investigate Methanol WaterFuel Compositions for Compression Ignition Engines 1.1 Summary

This report summarises the results obtained during an experimentalprogramme undertaken by the University of Melbourne on the performanceand engine-out emissions of different methanol based fuels in acompression ignition engine.

The fuels tested were mixtures of methanol, water, dimethyl ether (DME)and diethyl ether (DEE). As methanol is not normally a compressionignition fuel, two ignition promoter systems were used. The firstconsisted of an inlet air pre-heater. By heating the engine inlet air toup to 150deg C. (an imposed safety limit), higher temperatures arereached near the end of the compression stroke, at which point the mainfuel charge is injected. In some cases, these temperatures were highenough such that compression ignition of the injected fuel occurred.

The second system for promoting ignition involved the continuousinjection (i.e. fumigation) of gaseous di-methyl ether (DME) into theengine's inlet port. Because DME has a relatively low ignitiontemperature and a high cetane number, the DME auto-ignites as theair/fumigant mixture is compressed during the compression stroke, thusreleasing thermal energy that in turn can ignite the main fuel charge.

The tests were conducted on a modified 1D81 Hatz, single cylinder dieselengine, mounted on an in-house built motoring/absorbing dynamometerfacility. In its unmodified state, this naturally aspirated engineproduces up to 10 kW of shaft power from a single cylinder ofapproximately 670 cc volume. It is very likely that the absoluteperformance of all fuels tested will be better in larger engines, as itis commonly known in the engine community that peak engine efficiencyincreases with engine size due to fundamental physical laws.

As such, it is considered that the engine performance for the non-dieselfuels in the current test programme should be viewed relative to thediesel fuelled result on this same engine. Specifically, if comparableor better performance is achieved with a given alternative fuel relativeto diesel in this engine, it is likely that this relative performancecan also be achieved on a larger engine. Of course, maximising theabsolute performance of a given fuel on a given engine requires furtheroptimisation, and which should improve engine performance.

The general observations from this experimental programme are asfollows.

1. Fumigated Engine Tests

These results show that at the more efficient operating conditions, thefumigated engine produced comparable efficiency, lower NO emissions andmuch lower particulate emissions than the diesel engine.

2. Heated Inlet Air Tests

These results show that engine out NO emissions were comparable to thediesel engine. As with the fumigated engine runs, much lower particulateemissions than the diesel engine were again observed. Further work isrequired to improve the efficiency of the engine in this mode ofoperation.

1.2 Experimental Methods

The tests were conducted on a modified 1D81 Hatz diesel engine, mountedon an in-house built motoring/absorbing dynamometer facility. FIG. 10sets out a Process and Instrumentation Diagram for the facility. Theunmodified engine specifications are detailed on Table 1 below. Thesespecifications were not changed during the engine testing.

The modifications made to the engine consisted of the following.

-   -   Replacement of the mechanical fuel injector and fuel pump with a        solenoidally driven injection system and separate fuel pump and        injection system.    -   An electronically commanded common rail diesel injector was used        to fuel the system. This injector (Bosch, model 0 445 110        054-RE) delivered a significantly higher volume flow rate than        the injector on the unmodified engine, such that the highest        water containing fuels in Table 2 could be delivered whilst        achieving the same air/fuel ratio as both the diesel and pure        methanol fuels.    -   This injector is oversized for this engine, and so should result        in a significant reduction in engine performance even when        running on the same diesel fuel as the unmodified engine. As a        result, the proper reference for testing the alternative fuels        listed in Table 2 is the same, modified system running on        diesel, the results of which are listed in Tables 3, 4 and 5. It        is anticipated that further testing, specifically of fuels with        the lower water content, will enable use of a smaller injector        and thus significant improvements in engine performance.    -   As FIG. 10 shows, the fuels were mixed into a pressurised        storage vessel such that the DME did not transition into the gas        phase prior to injection into the engine. This vessel was always        at between 5 and 10 bar during testing. The liquid fuel leaving        this vessel was then pressurised by a Haskel, air drive pump, up        to 800 bar before being injected into the engine. A high        pressure accumulator was used to ensure that the fuel line        pressure remained constant during the tests.    -   The fuel flow rate was measured by suspending the pressurised        storage vessel on a load cell, and measuring the rate of change        of the vessel's mass during each test.    -   Extension of the inlet manifold.    -   This was done to connect both the inlet air pre-heater and the        DME fumigation inlet. Both systems were used as ignition        promoters of the main fuel charge.    -   Extension of the exhaust manifold to connect all the emission        analysis systems.    -   A Kistler piezoelectric pressure transducer.    -   Installed on the engine's cylinder head in order to record the        in-cylinder pressure.    -   Use of Shell Helix Racing 10W60 oil for all tests.    -   This is a synthetic oil.

The exhaust out emissions were analysed using a number of independentsystems.

-   -   A MAHA particulate matter meter.    -   This device gives a gravimetric measure of the particulate        matter in the engine exhaust.    -   A Bosch UEGO sensor.    -   This is a production device that measures the air-fuel ratio.        Whilst it has been developed for hydrocarbon fuels, comparison        with the measured air-fuel ratio from the ADS9000 emissions        bench demonstrated that it functioned well for all fuels tested        other than those with greater than 50% water content (FIG. 4).    -   An ADS9000 emissions bench.    -   This device measured the engine out emissions of NO. Prior to        sampling, the exhaust sample is passed through unheated lines        and a water trap, and thus the water content of the sampled        gases should be close to saturated at ambient conditions. The        ADS9000 was calibrated before and during the test programme        using calibration gases for all measured quantities and a gas        divider.    -   A Gasmet FTIR emissions analyser.    -   This device was calibrated using appropriate calibration gases        and zeroed with high purity nitrogen as per the supplier's        instruction.

Each fuel was tested at the steady state speed of 2000 rpm and a lambdavalue of 2 (i.e. 100% excess air). The unmodified engine operated at alambda of approximately 1.5. The leaner operation was chosen since thefirst tests at lambda 1.5 with pure methanol resulted in engine seizuredue to an over-advanced injection in one instance. No further engineseizures were experienced at lambda 2.

The overall test engine procedure was as follows.

1. Heated Inlet Runs.

The inlet air was first increased to 150deg C.

The injection duration was set by the lambda value of 2, and the startof injection set to top-dead-centre.

The heater controller then reduced the inlet temperature whilst theengine ran, until positive engine torque was no longer sustained. Theheater inlet controller then set the inlet temperature to a degreehigher than when operation ceased.

The start of injection was then advanced with the dynamometer controllermaintaining constant engine speed, until the engine torque reachedso-called ‘maximum brake torque (MBT)’. MBT is the most efficientoperating condition at a constant engine speed and air/fuel ratio.

The resulting injection timing (start and duration) and other measuredquantities were logged at this operating condition.

2. Fumigated Inlet Runs.

The engine was established at a smooth running condition with a high DMEflow rate.

The main fuel injection duration was set by the lambda value of 2 andthe start of injection timing was set at top-dead-centre.

The DME flow rate was then reduced whilst increasing the main fuel flowrate to maintain constant lambda, until the brake torque reached amaximum.

The start-of-injection timing was then advanced until MBT timing wasachieved, whilst continuing to adjust the main fuel flow rate tomaintain lambda if required.

The resulting injection timing (start and duration) and other measuredquantities were logged at this operating condition.

3. Diesel Engine Run.

The start-of-injection timing was advanced to MBT whilst maintaininglambda at 2 via the injection duration.

The specifications of the fuels were as follows.

-   -   Methanol, 99.8%+ purity    -   De-ionised water, 99.8%+ purity    -   dimethyl ether (DME), 98%+ purity    -   di-ethyl ether (DEE), 98%+ purity

1.3 Results

The results of the test work are presented in the tables below.

TABLE 1 unmodified engine specifications Technical Data Units 1D81Number of Cylinders 1 Bore × stroke [mm] 100 × 85 Displacement [L] 0.667Mean piston speed at 3000 rpm [m/s] 8.5 Compression ratio 20.5

TABLE 2 schedule of fuels tested (those in bold did not produce net workoutput even with inlet air at 150 deg C.) With Fumigation With HeaterMain fuel composition Main fuel composition (% by volume) (% by volume)MeOH Water DME DEE MeOH water DME DEE 100 0 0 0 100 0 0 0 95 5 0 0 85 150 0 90 10 0 0 77.5 22.5 0 0 70 30 0 0 70 30 0 0 50 50 0 0 50 50 0 0 3565 0 0 35 65 0 0 95 0 5 0 95 0 5 0 90 5 5 0 80 15 5 0 85 10 5 0 72.522.5 5 0 65 30 5 0 65 30 5 0 45 50 5 0 45 50 5 0 30 65 5 0 30 65 5 0 900 10 0 90 0 10 0 85 5 10 0 75 15 10 0 80 10 10 0 67.5 22.5 10 0 60 30 100 60 30 10 0 40 50 10 0 40 50 10 0 25 65 10 0 25 65 10 0 80 0 20 0 80 020 0 75 5 20 0 65 15 20 0 70 10 20 0 57.5 22.5 20 0 50 30 20 0 50 30 200 30 50 20 0 30 50 20 0 15 65 20 0 15 65 20 0 90 0 0 10 90 0 0 10 85 5 010 75 15 0 10 80 10 0 10 67.5 22.5 0 10 60 30 0 10 60 30 0 10 40 50 0 1040 50 0 10 25 65 0 10 25 65 0 10

TABLE 3 Diesel performance data Diesel Performance Data LHV Tin ToutInjection Time Inj. Duration Lambda Speed Torque Power Airflow Main FuelDME Fum (MJ/kg) ° C. ° C. DBTDC CAD — rpm Nm kW g/s g/s g/s BTE % 4322.4 401 4 10 2.13 1975 22.1 4.6 13.1 0.46 0 23.0%

TABLE 4 Diesel ADS9000 emissions data Maha and ADS 9000 (calculated wet)Emissions Particulate NO NO Lambda mg/m{circumflex over ( )}3 ppm g/kWh— 140 440 4.9 1.9

TABLE 5 performance data with DME fumigation With Fumigation PerformanceData Main fuel composition Inj. Time Inj. Main (% by volume) LHV TinTout CAD Duration Lambda Speed Torque Power Airflow Fuel DME MeOH waterDME DEE MJ/kg ° C. ° C. BTDC CAD UEGO rpm Nm kW g/s g/s g/s BTE % 100 00 0 20.0 27 339 6 16 2.1 1977 18.4 3.8 12.8 0.69 0.168 20.3% 95 5 0 018.8 26 318 6 18 2.1 1981 18.8 3.9 12.9 0.74 0.168 20.9% 90 10 0 0 17.527 327 6 19 2.1 1985 17.9 3.7 12.9 0.75 0.168 20.7% 70 30 0 0 13.0 26301 6 22 2.1 1984 16.4 3.4 12.9 0.89 0.210 19.3% 50 50 0 0 8.8 25 241 1026 2.2 1984 12.5 2.6 12.9 1.01 0.252 16.0% 35 65 0 0 6.0 25 191 28 342.1 1982 10.0 2.1 12.9 1.32 0.280 12.9% 95 0 5 0 20.4 27 367 8 21 2.11981 20.5 4.3 12.9 0.77 0.168 20.7% 90 5 5 0 19.1 27 349 12 21 2.1 198420.9 4.3 12.9 0.80 0.168 21.5% 85 10 5 0 17.9 26 337 12 22 2.1 1980 20.04.1 12.9 0.80 0.168 21.7% 65 30 5 0 13.3 24 296 16 28 2.1 1977 18.7 3.912.8 1.03 0.182 20.3% 45 50 5 0 9.1 24 251 20 33 2.1 1979 14.8 3.1 12.81.20 0.238 17.2% 30 65 5 0 6.2 24 194 30 34 2.0 1980 10.4 2.2 12.8 1.320.252 13.9% 90 0 10 0 20.8 24 354 10 21 2.0 1979 21.7 4.5 12.8 0.800.168 20.9% 85 5 10 0 19.5 24 352 12 23 2.0 1977 22.1 4.6 12.8 0.850.168 21.4% 80 10 10 0 18.2 23 335 16 21 2.0 1977 21.7 4.5 12.8 0.830.168 22.3% 60 30 10 0 13.6 24 294 18 25 2.0 1979 18.6 3.9 12.8 0.980.182 20.8% 40 50 10 0 9.4 24 258 20 30 2.0 1983 15.6 3.2 12.9 1.180.238 18.0% 25 65 10 0 6.4 24 180 30 32 2.3 1976 8.3 1.7 12.8 1.19 0.26611.2% 80 0 20 0 21.6 24 353 10 19 2.0 1980 22.0 4.6 12.8 0.72 0.21021.1% 75 5 20 0 20.2 26 352 10 19 2.1 1981 21.1 4.4 12.9 0.69 0.21021.8% 70 10 20 0 19.0 24 327 10 18 2.1 1977 19.6 4.1 12.8 0.73 0.21020.3% 50 30 20 0 14.2 23 300 16 23 2.1 1976 17.4 3.6 12.8 0.86 0.23818.9% 30 50 20 0 9.9 23 271 18 30 2.0 1978 15.0 3.1 12.8 1.09 0.26616.8% 15 65 20 0 6.9 22 204 30 46 2.2 1978 10.7 2.2 12.8 1.27 0.30812.6% 90 0 0 10 21.3 33 377 6 16 2.1 1987 19.2 4.0 12.9 0.69 0.168 20.4%85 5 0 10 20.1 32 381 6 20 2.0 1986 19.5 4.1 12.9 0.74 0.168 20.6% 80 100 10 18.8 31 344 10 20 2.1 1987 19.1 4.0 12.9 0.77 0.168 20.6% 60 30 010 14.1 30 313 12 24 2.1 1987 17.9 3.7 12.9 0.93 0.182 20.2% 40 50 0 109.9 30 279 16 32 1.9 1985 16.6 3.4 12.9 1.34 0.224 17.4% 25 65 0 10 7.030 210 30 38 2.1 1989 11.3 2.4 12.91 1.34 0.266 13.8%

TABLE 6 performance data with heated inlet air Performance Data WithHeater Inj. Main fuel composition Time Inj. Main (% by volume) LHV TinTout CAD Duration Lambda Speed Torque Power Airflow Fuel DME MeOH waterDME DEE (MJ/kg) ° C. ° C. BTDC CAD UEGO rpm Nm kW g/s g/s g/s BTE % 1000 0 0 20.0 100.0 377 10 16 2.01 1988 12.2 2.5 10.4 0.73 0 17.5% 85 15 00 16.4 107.5 334 14 18 2.08 1992 10.6 2.2 10.3 0.79 0 17.2% 77.5 22.5 00 14.6 126.1 307 16 19 2.10 1991 7.4 1.5 9.8 0.84 0 12.5% 95 0 5 0 20.4106.8 357 10 14 2.10 1987 10.6 2.2 10.3 0.61 0 17.7% 80 15 5 0 16.7108.3 348 12 18 2.04 1983 10.6 2.2 10.2 0.74 0 17.7% 72.5 22.5 5 0 15.0120.5 339 16 20 1.94 1981 9.5 2.0 9.9 0.83 0 15.8% 90 0 10 0 20.8 114.0381 10 17 1.99 1988 11.1 2.3 10.1 0.65 0 17.2% 75 15 10 0 17.0 113.6 33312 17 2.13 1987 10.1 2.1 10.1 0.72 0 17.1% 67.5 22.5 10 0 15.28 105.9347 14 20 2.03 1989 11.2 2.3 10.3 0.86 0 17.8% 80 0 20 0 21.6 113.4 37810 15 2.10 1989 10.6 2.2 10.1 0.60 0 17.1% 65 15 20 0 17.7 106.5 337 1418 2.11 1990 10.7 2.2 10.3 0.71 0 17.7% 57.5 22.5 20 0 15.9 117.8 336 1620 2.05 1991 9.5 2.0 10.0 0.78 0 16.0% 90 0 0 10 21.3 100.7 365 10 162.04 1984 12.0 2.5 10.4 0.67 0 17.5% 75 15 0 10 17.6 111.9 327 12 172.15 1990 9.9 2.1 10.1 0.72 0 16.3% 67.5 22.5 0 10 15.9 124.6 320 14 182.03 1988 8.4 1.8 9.8 0.76 0 14.6%

TABLE 7 MAHA and ADS 9000 (calculated wet) emissions with DME fumigationWith Fumigation Maha and ADS 9000 Main fuel composition (calculated wet)Emissions (% by volume) Particulate NO NO Lambda MeOH water DME DEEmg/m{circumflex over ( )}3 ppm g/kWh — 100 0 0 0 1 106 1.5 2.0 95 5 0 01 89 1.2 2.0 90 10 0 0 1 37 0.5 2.0 70 30 0 0 1 12 0.2 2.1 50 50 0 0 111 0.2 2.2 35 65 0 0 1 18 0.5 2.2 95 0 5 0 1 57 0.7 1.9 90 5 5 0 1 1411.7 1.9 85 10 5 0 1 83 1.1 2.0 65 30 5 0 1 19 0.3 2.0 45 50 5 0 1 19 0.42.1 30 65 5 0 1 21 0.6 2.3 90 0 10 0 1 99 1.2 1.9 85 5 10 0 1 97 1.1 1.980 10 10 0 1 192 2.3 1.9 60 30 10 0 1 17 0.2 2.0 40 50 10 0 1 12 0.2 2.125 65 10 0 1 28 0.9 2.4 80 0 20 0 1 111 1.3 1.9 75 5 20 0 1 153 1.8 1.970 10 20 0 1 88 1.1 2.0 50 30 20 0 1 54 0.8 2.0 30 50 20 0 1 9 0.2 2.015 65 20 0 1 15 0.4 2.2 90 0 0 10 1 92 1.2 1.9 85 5 0 10 1 72 0.9 1.9 8010 0 10 1 65 0.9 1.9 60 30 0 10 1 21 0.3 2.0 40 50 0 10 1 15 0.2 2.0 2565 0 10 1 20 0.5 2.2

TABLE 8 MAHA and ADS 9000 (calculated wet) emissions with heated inletair With Heater Maha and ADS 9000 Main fuel composition (calculated wet)Emissions (% by volume) Particulate NO NO Lambda MeOH water DME DEEmg/m{circumflex over ( )}3 ppm g/kWh — 100 0 0 0 1 355 5.93 2.0 85 15 00 1 158 3.02 2.0 77.5 22.5 0 0 1 85 2.27 2.1 95 0 5 0 1 356 6.65 2.1 8015 5 0 1 146 2.79 2.0 72.5 22.5 5 0 1 100 2.09 2.0 90 0 10 0 1 371 6.552.0 75 15 10 0 1 136 2.67 2.1 67.5 22.5 10 0 1 106 1.94 2.1 80 0 20 0 1358 6.54 2.1 65 15 20 0 1 249 4.68 2.0 57.5 22.5 20 0 1 139 2.90 2.0 900 0 10 1 290 4.89 2.0 75 15 0 10 1 187 3.73 2.1 67.5 22.5 0 10 1 1393.20 2.1

TABLE 9 combustion analysis data with DME fumigation With FumigationMain fuel composition Combustion Analysis (% by volume) IMEP PMEP PP LPPPPRR LPPRR MeOH water DME DEE kPa kPa kPa DATDC kPa/deg CA CoV % 100 0 00 717.5 −28.0 8466.5 6.5 357.4 −12.4 2.33% 95 5 0 0 723.3 −28.6 9195.15.3 390.1 −2.2 3.93% 90 10 0 0 701.9 −27.9 8277.2 5.9 355.4 −12.5 2.39%70 30 0 0 666.2 −27.2 8194.6 6.4 388.3 −12.9 4.10% 50 50 0 0 577.2 −27.19624.9 3.3 490.6 −14.3 3.82% 35 65 0 0 535.3 −25.5 10573.9 2.9 430.2−6.0 3.67% 95 0 5 0 776.4 −29.3 8457.0 5.7 319.4 −11.5 3.75% 90 5 5 0773.3 −29.0 9387.6 5.1 465.8 −0.8 4.16% 85 10 5 0 756.3 −28.5 9340.8 4.9431.3 −1.1 4.66% 65 30 5 0 740.4 −28.9 9931.3 4.2 483.6 −1.4 3.46% 45 505 0 670.0 −27.7 9767.1 4.8 395.5 −12.9 4.29% 30 65 5 0 570.1 −26.910951.5 2.5 466.6 −4.5 4.37% 90 0 10 0 775.3 −29.4 9003.2 5.5 344.9 −9.33.94% 85 5 10 0 771.7 −29.0 9320.6 4.9 405.6 −1.7 3.47% 80 10 10 0 781.8−28.5 10387.8 4.0 548.1 −5.3 4.24% 60 30 10 0 708.4 −25.1 10361.1 3.3580.2 −4.0 3.73% 40 50 10 0 656.1 −25.2 10675.0 2.5 502.5 −4.5 2.41% 2565 10 0 583.6 −26.8 10161.1 4.1 373.3 −11.5 2.92% 80 0 20 0 796.8 −29.39159.7 5.4 352.4 −10.3 2.93% 75 5 20 0 802.3 −29.9 9286.8 5.4 366.5−12.5 3.09% 70 10 20 0 755.6 −27.9 9425.7 5.2 394.6 −13.1 4.05% 50 30 200 * 30 50 20 0 * 15 65 20 0 * 90 0 0 10 738.6 −30.2 7752.5 5.7 345.2−13.0 4.62% 85 5 0 10 747.2 −29.9 8036.1 5.6 334.5 −12.9 3.67% 80 10 010 738.3 −28.5 8916.7 5.4 344.0 −9.3 3.24% 60 30 0 10 708.2 −28.3 9197.54.7 365.3 −8.1 3.90% 40 50 0 10 664.7 −26.6 9777.8 3.7 417.9 −14.2 3.90%25 65 0 10 572.4 −24.5 10794.8 2.9 468.6 −3.8 4.35% * These entries wereunavailable due to failure of the pressure transducer during testing.

TABLE 10 combustion analysis data with heated inlet air With Heater Mainfuel composition Combustion Analysis (% by volume) IMEP PMEP PP LPP PPRRLPPRR MeOH water DME DEE kPa kPa kPa DATDC kPa/deg DATDC CoV % 100 0 0 0523.4 −21.5 7614.1 5.9 373.2 −0.4 4.72% 85 15 0 0 517.1 −21.3 7900.8 5.7481.3 0.5 4.42% 77.5 22.5 0 0 431.0 −17.0 7420.6 5.6 390.8 0.0 4.11% 950 5 0 531.3 −20.4 7402.2 6.4 370.7 0.9 4.36% 80 15 5 0 556.3 −21.77440.5 5.8 382.4 1.6 5.22% 72.5 22.5 5 0 505.6 −19.8 7963.9 4.9 524.1−1.1 3.90% 90 0 10 0 528.6 −20.3 7391.3 6.0 381.6 1.7 5.22% 75 15 10 0505.3 −20.3 7408.9 5.7 399.9 0.9 4.20% 67.5 22.5 10 0 486.5 −19.4 7595.25.6 440.6 0.1 4.64% 80 0 20 0 535.7 −19.9 7089.4 5.9 328.3 −0.8 4.08% 6515 20 0 554.7 −20.2 7807.8 5.8 466.6 −0.3 4.17% 57.5 22.5 20 0 489.6−18.8 7861.2 4.7 509.5 −1.4 4.54% 90 0 0 10 557.2 −21.6 7493.1 6.5 384.31.6 3.75% 75 15 0 10 511.9 −20.9 7585.1 6.6 406.1 2.8 4.66% 67.5 22.5 010 478.7 −20.3 7636.8 5.2 464.9 −0.9 3.50%

1.5 Further Test Work

Further test work was conducted to explore additional fuel and fumigantcombinations, and the results of those tests are summarized in Tables 11and 12 below. Of note is the following:

-   -   Overall, the engine efficiencies at 1000 rpm are lower than for        the same or similar fuels at higher engine speeds. This is based        on the fact that the unmodified Hatz engine had a peak        efficiency at approximately 2000 rpm, and was to be expected.        When used in larger engines designed for peak efficiency at a        lower rpm, the efficiencies using the fuels would be improved.    -   Emissions of NO using the ADS9000 device are not presented due        to failure of this sensor during this testing programme.    -   The fuel injector failed during test number 25. The data logged        for this test still appeared to be reasonable, as the failure        was late in the test, and so is included in this Addendum. Of        note is the comparative performance of runs 25 and 27, which        have very similar main fuel composition, other than the        additives.

TABLE 11 performance data with DME fumigation Fumigated Run Main % byVol Additives by weight Main fuel composition with additives (% by mass)LHV No MeOH EthOH water DME DEE Formal. Aspro. Other MeOH EthOH waterDME DEE Formal. Aspro. Other (MJ/kg) 22 70 0 30 0 0 0 0 0 64.9 0.0 35.10 0 0 0 0 13.0 23 70 0 30 0 0 0 0 0 64.9 0.0 35.1 0 0 0 0 0 13.0 24 70 030 0 0 0 0 0 64.9 0.0 35.1 0 0 0 0 0 13.0 25 — — — 0 0 0 2.5 0.4 93.20.0 3.9 0 0 0 2.5 0.4 18.6 27 — — — 0 0 2 0 0.4 93.7 0.0 3.9 0 0 2 0 0.418.7 28 — — — 0 0 0 0 0.4 79.7 0.0 19.9 0 0 0 0 0.4 15.9 29 — — — 0 0 00 0 40 0.0 60.0 0 0 0 0 0.0 8.0 30 — — — 0 0 0 0 0 93 0.0 7.0 0 0 0 00.0 18.6 24 70 0 30 0 0 0 0 0 64.9 0.0 35.1 0 0 0 0 0 13 rep PerformanceData Run Tin Tout Injection Time Lambda Speed Torque Power Airflow MainFuel DME No deg C. deg C. CAD BTDC UEGO rpm Nm kW g/s g/s g/s BTE % 2239 209 0 2.1 1000 9.1 1.0 6.3 0.41 0.047 14.4% 23 56 214 0 2.0 998 8.30.9 5.9 0.41 0.039 13.4% 24 81 216 0 2.1 999 4.8 0.5 5.5 0.38 0.032 8.6% 25 32 228 0 2.0 992 12.1 1.3 6.4 0.31 0.05 17.5% 27 26 233 0 2.1994 12.3 1.3 6.5 0.32 0.043 17.6% 28 26 220 0 2.1 993 10.8 1.1 6.5 0.340.056 16.0% 29 26 193 0 2.1 990 7.0 0.7 6.5 0.52 0.102 10.2% 30 78 339 02.1 1978 11.1 2.3 11.0 0.67 0.106 14.7% 24 rep 83 224 0 2.0 995 5.9 0.65.5 0.39 0.031 10.4% Maha and ADS 9000 (calculated wet) Emissions RunParticulate NO NO Lambda No mg/m{circumflex over ( )}3 ppm g/kWh — 22 1— — 2.1 23 1 — — 2.2 24 1 — — 2.1 25 1 — — 1.9 27 1 — — 2.1 28 1 — — 2.129 1 — — 2.1 30 1.2 — — 2.1 24 rep 1 — — 2.0

TABLE 12 performance data with heated inlet air With Heater Run Main %by Vol Additives by weight Main fuel composition with additives (% bymass) LHV No MeOH EthOH water DME DEE Formal. Aspro. Other MeOH EthOHwater DME DEE Formal. Aspro. Other (MJ/kg)  3 70 0 30 5 0 0 0 0 61.7 0.033.3 5 0 0 0 0 13.8  6 70 0 30 0 8 0 0 0 59.7 0.0 32.3 0 8 0 0 0 14.7  770 0 30 0 20 0 0 0 51.9 0.0 28.1 0 20 0 0 0 17.2  8 70 0 30 20 0 0 0 051.9 0.0 28.1 20 0 0 0 0 16.2 11 70 0 30 0 0 4 0 0 62.3 0.0 33.7 0 0 4 00 12.5 18 70 0 30 0 0 1 0 0 64.3 0.0 34.7 0 0 1 0 0 12.9 21 20 50 30 5 00 0 0 17.5 44.3 33.2 5 0 0 0 0 16.9 Performance Data Main DME Run TinTout Injection Time Lambda Speed Torque Power Airflow Fuel Fum No deg C.deg C. DBTDC UEGO rpm Nm kW g/s g/s g/s BTE %  3 141.1 229.2 0 2.06 9953.4 0.4 4.7 0.41 — 6.5%  6 154.7 229 0 2.08 993 2.0 0.2 4.6 0.33 — 4.2% 7 155.4 237 0 2.09 991 2.3 0.2 4.5 0.29 — 4.7%  8 149.6 244 0 2.02 9963.2 0.3 4.6 0.32 — 6.3% 11 Did not fire 18 Did not fire 21 150.8 246 02.03 994 3.2 0.3 4.6 0.28 — 7.0% Maha and ADS 9000 (calculated wet)Emissions Run Particulate NO NO Lambda No mg/m{circumflex over ( )}3 ppmg/kWh — 3 1 — — 2.0 6 1 — — 2.2 7 1 — — 2.2 8 1 — — 2.1 11  — — — — 18 — — — — 21  1 — — 2.1

1.5 Comparison Tables Between % Volume and % Mass in Fuel Compositions

The tables in the test results outlined at 1.1 to 1.4 above are based onrelative amounts of components in the main fuel composition measured byvolume. The following tables 13 and 14 enable a conversion to be madebetween volume and weight % for the fuel compositions.

TABLE 13 Comparison tables between % volume and % mass - Fumigation WithFumigation Main fuel composition Main fuel composition (% by volume) (%by mass) MeOH water DME DEE MeOH water DME DEE 100 0 0 0 100.0 0.0 0.00.0 95 5 0 0 93.8 6.2 0.0 0.0 90 10 0 0 87.7 12.3 0.0 0.0 70 30 0 0 64.935.1 0.0 0.0 50 50 0 0 44.2 55.8 0.0 0.0 35 65 0 0 29.9 70.1 0.0 0.0 950 5 0 95.8 0.0 4.2 0.0 90 5 5 0 89.5 6.3 4.2 0.0 85 10 5 0 83.4 12.4 4.10.0 65 30 5 0 60.7 35.4 3.9 0.0 45 50 5 0 40.0 56.2 3.8 0.0 30 65 5 025.8 70.6 3.6 0.0 90 0 10 0 91.4 0.0 8.6 0.0 85 5 10 0 85.2 6.3 8.5 0.080 10 10 0 79.1 12.5 8.3 0.0 60 30 10 0 56.4 35.7 7.9 0.0 40 50 10 035.8 56.6 7.6 0.0 25 65 10 0 21.6 71.1 7.3 0.0 80 0 20 0 82.6 0.0 17.40.0 75 5 20 0 76.4 6.4 17.2 0.0 70 10 20 0 70.3 12.7 16.9 0.0 50 30 20 047.7 36.2 16.1 0.0 30 50 20 0 27.3 57.4 15.3 0.0 15 65 20 0 13.2 72.114.8 0.0 90 0 0 10 90.9 0.0 0.0 9.1 85 5 0 10 84.7 6.3 0.0 9.0 80 10 010 78.7 12.4 0.0 8.9 60 30 0 10 56.1 35.5 0.0 8.4 40 50 0 10 35.6 56.30.0 8.0 25 65 0 10 21.5 70.7 0.0 7.8

TABLE 14 Comparison tables between % volume and % mass - Inlet AirPreheating With Heater Main fuel composition Main fuel composition (% byvolume) (% by mass) MeOH water DME DEE MeOH water DME DEE 100 0 0 0100.0 0.0 0.0 0.0 85 15 0 0 81.8 18.2 0.0 0.0 77.5 22.5 0 0 73.2 26.80.0 0.0 95 0 5 0 95.7 0.0 4.3 0.0 80 15 5 0 77.6 18.3 4.1 0.0 72.5 22.55 0 69.0 27.0 4.0 0.0 90 0 10 0 91.4 0.0 8.6 0.0 75 15 10 0 73.3 18.58.2 0.0 67.5 22.5 10 0 64.7 27.2 8.1 0.0 80 0 20 0 82.6 0.0 17.4 0.0 6515 20 0 64.5 18.8 16.8 0.0 57.5 22.5 20 0 55.9 27.6 16.4 0.0 90 0 0 1090.9 0.0 0.0 9.1 75 15 0 10 72.9 18.4 0.0 8.8 67.5 22.5 0 10 64.3 27.10.0 8.6

1.6 Observations on the Test Results Reported in Sections 1.1 to 1.5.Water and Ether Plus DME Fumigant:

The work reported above demonstrates that that water has some keyproperties which make it a useful addition to a methanol fuel:

-   -   1. If injected with the combustible methanol fuel, up to a        point, the efficiency does not decrease but rather increases to        an optimal point, and then decreases as the proportion of water        continues to rise. It has been postulated by the applicants that        the increase in efficiency may be due to a combination of        factors such as the following factors:        -   a. the spectral properties of water such as emissivity and            absorption coefficient are superior relative to methanol            across the heating (eg infrared IR) band, which assists in            the uptake of radiant heat into the droplets of mixed fuel            and water, as the methanol evaporates from the droplet at an            accelerated rate, since methanol would share this higher            rate of heat uptake and vaporise first. The emissivity of            water is reported in the literature is between 0.9 and 1.0            ie nearly a blackbody to infrared radiation, while methanol            is less than half that value at close to 0.4.        -   b. The thermal conductivity of water is greater than            methanol        -   c. The thermal diffusivity of water is greater than            methanol.        -   d. Points b. and c. above would lead to greater transfer of            heat within a droplet with water present, again accelerating            the conversion of liquid phase methanol to gas as methanol            concentration decreases as the droplets shrink:

THERMAL THERMAL DIFFUSIVITY CONDUCTIVITY MM2/SEC W/K · M 100% METHANOL0.103 0.199  75% METHANOL 0.102 0.250  50% METHANOL 0.106 0.340  25%METHANOL 0.118 0.470 100% WATER 0.149 0.605 Taken from ThermochimicaActa 492 (2009) p95-100

-   -   2. The work reported above provides evidence of the viability of        a water methanol fuel through the demonstration of its smooth        operation when running even at high water levels with a suitable        amount of ignition assistance in terms of fumigant. From the        data presented in FIG. 7, which is derived from the work        reported above, it is shown that there is a peak of break        thermal efficiency achieved when the water content is in the        range of about 12% to 23% by weight of the main fuel        composition. The zone of improved BTE is for water contents        between 2% and 32%, with an optimum being achieved in the region        of close to 16-18% with DME fumigant. This was a surprising        result. It was unexpected that injecting such high levels of        water into the combustion chamber would enable a compression        ignition engine to operate with acceptable operation in terms of        COV of IMEP. (coefficient of variation of indicated mean        effective pressure).

From the experimental data reported above, a lower ranking BTE performerin most cases was undiluted methanol, with good performance obtained bymixtures which included DME in the 4-9% weight range.

As the water content went beyond approximately 30% by weight in fuelswhich contained the amounts of DME mentioned previously, the efficiencydropped back to levels that were consistent with the fuels beingcombusted with no water present.

It was of note that the fuels of about 70% water combusted in theengine, albeit at half the efficiency due in part to the higher exhaustwater content.

FIG. 8 provides a graphical representation of the ether content of themain fuel, in weight %, and the consequent BTE of the fuel. The bracket(}) is used to mark the points relating to the use of diethylether asthe ether component in the fuel composition, whereas the ether used inthe other plotted points was dimethyl ether. FIG. 8 indicates a lift inBTE of some 1.5% by introducing 4% DME to the liquid phase at approx 16%water content, compared to the undiluted methanol case. In general, theresults provided through the use of an amount of ether within the boxshown by a dashed line provides advantages to the main fuel composition.Increasing the ether content above the 10% level (i.e. outside the boxto the right of the figure) introduces additional cost without acorresponding process improvement or advantage.

At low water levels the benefits of 16% DME compared to 4% were small,and 4% DME outperformed 16% DME at water contents higher than about 6%.

Approx 8% DME by weight had slightly higher BTE than 4% DME throughoutthe water content range, the difference averaging about 0.3% up to amaximum of about 36% water in fuel.

Di ethyl ether (DEE, bracketed points) in fuel showed a weaker BTE inthe lower water ranges where the performance was similar to neatmethanol, however as the water content in fuel rose above about 25% DEEat approximately 8% improved its performance to match that of DME.

In terms of brake thermal efficiency DEE might not be chosen ahead ofDME in a methanol water fuel unless other reasons such as volatility orvapour pressure prevailed.

Effect of Water and Fumigant on NO:

In a fumigated environment where a coolant such as water is applied, itcould not be predicted that a reduction of NO would be achieved and theextent of NO reduction could not be predicted. The test work shows thatthe NO reduction was quite dramatic as water levels increased, showing atrough of 0.2 grams/kw-hr at 36% wt water, as shown in the FIG. 9.

FIG. 10 provides another illustration of the effect that increasing thewater content has on NOX in the exhaust. The 4% and 8% DME lines showedthe best response to NOX formation even at high inlet air temperatures.The same trend can be seen in the case of fumigation, case of decreasingNOX as water levels increase 16.5% DME and 8.8% DEE showed higher levelsof NO compared to the low DME cases. All heated runs with no waterproduced higher NO than diesel fuel without preheat

From the above data and accompanying Figures it is evident that oneoperating zone of merit involves the use of a main fuel compositioncomprising methanol and 20-22% by weight water and 4-6% wt DME in themain fuel composition, with fumigation. This fuel would achieve goodefficiency and low NO. The desirable fuel operation zone can be furtherexpanded with acceptable operation of the CI engine, as described indetail in other sections of this application.

Diesel fuel on the same engine by contrast achieved 4.9 grams/kw-hr atlambda 2 and 2000 rpm (the lambda and speed of all fumigation tests inthese graphs)

Fumigant:

The use of a fumigant (or fumigation) has not been considered previouslywith complex fuel compositions, particularly with fuel compositionscomprising water and methanol, and optionally with other additives suchas DME. Certainly there have been no reports of commercial uptake ofsuch techniques. This may be due to the fact that it might have beenconsidered that such a fuel would be unlikely to work well at all, giventhe low heating value of methanol, which is further impaired by mixingit with a high latent heat diluent such as water. The use of a fuelcontaining a large water component is also counter-intuitive as water isnormally used to put out fires rather than help them burn.

To investigate this space a single cylinder engine with similar capacityof a cylinder of a 5 litre V8 engine was used, with larger injectorsinstalled to overcome the low heating value per litre of some of thefuels to be tested.

These larger injectors had the effect of reducing the engine efficiency,however as a comparison between fuels, provided mirror conditionsapplied, the validity of the comparisons has been acknowledged by enginetesting professionals.

Oversized injectors were required in the specific operating conditionsof the test, and the engine was operated at high rpm due to the smallengine size, but further work would enable modification of these factorsthis with a consequent reduction in the relative amount of fumigant(ignition enhancer) injected into the inlet air of the engine. Theexperimental work carried out to support this application was carriedout at 2000 rpm and 1000 rpm, the latter being the lowest operable speedof the Hatz engine used for the programme.

Example 2 30%:70% Water:Methanol Fuel with Fumigation

A fuel containing 70% methanol and 30% water, is introduced into thecombustion ignition engine schematically represented in FIG. 1

During different stages of operation of the engine (start-up, steadystate at low load, steady state at 50%-100% full load, idle, and soforth), different fumigant compositions may be used for fumigating theair inlet into the engine.

At start-up and initial idle, a larger weight % of fumigant with respectto the main fuel is fumigated into the air inlet. One suitable fumigantfor this stage of operation comprises 100% DME.

After the engine is running and load/rpm increased, the fumigant %amount and/or the % amount of ignition enhancer in the fumigant can bedecreased.

As the engine speed and load increases to full load, the weight % ofthis fumigant composition with respect to the main fuel can bedecreased, for example to 7-9% (refer FIG. 2 graph) by weight of themain fuel (100% DME in the fumigant, or dry basis (db)).

This enables operation of the engine to overcome the presence of waterat the 30% level in the main fuel composition.

Example 3 5%:95% Water:Methanol Fuel with Fumigant

Example 2 is repeated but with a 95% methanol to 5% water composition.Due to the higher methanol content, at the different stages of operationof the engine, the weight % of fumigant, or the % of DME in thefumigant, can be decreased as compared to Example 2, for example to 2-3%of fuel intake at full load (as 100% DME).

Example 4 1%:99% Water:Methanol Fuel with Fumigant

Example 2 is repeated but with a 99% methanol to 1% water composition.Due to the higher methanol content, at the different stages of operationof the engine, the weight % of fumigant, or the % of DME in thefumigant, can be decreased as compared to Example 2, for example to 0.5%to 2% of fuel intake at full load (as 100% DME).

Example 5 30%:70% Water:Methanol Fuel with Fumigation and Heat Method

Example 2 is repeated, but with preheating of the combustion airutilizing the methods described previously to 140° C. This modificationdecreases the fumigant required to 2-3% by weight compared to the 7-9%for Example 2.

Example 6 74:26% Water:Methanol with Fumigation and Heat Method

Example 3 is repeated but with a 26% methanol, 74% water fuelcomposition. This fuel composition is suitable for use in marineapplications—for operating ship CI engines. In this case, sea water canbe used as the heat sink if required to obtain the required level ofcondensation from the exhaust gas. In a marine situation, to ensuresafety in enclosed spaces via the presence of a non-flammable vapourphase on spillage, the water level in the fuel composition is about 74%(or more), with 26% (or less) of the fuel being methanol. This highwater content avoids the risk of ignition causing engine room fires.

The fuel is the Example may be pumped into the main fuel storage tank ina composition ready for use (i.e. with 74% water in the methanolcomposition). Alternatively, a pre-mix having a lower water level(compared to the in-use composition) may be pumped into the storagetank, and the water level increased through water dilution of thepre-mix final between storage and charging into the engine. The watersource may be any water source, and may for example be recycled water,or desalinated water. This option has advantages with respect to theweight of the fuel composition carried on the vessel.

The combustion of this fuel requires heat via the methods describedabove. DME vapour or spray is also fumigated into the air inlet toprovide sufficient means to ignite the fuel.

The amount of water in the exhaust gas can be calculated to be betweenabout 10-50%. This is based on the original water in the fuel and watercoming from combustion of the methanol, and DME, as well as water in theinlet air. This surprisingly high result arises from the high hydrogencontent of methanol (which contains more hydrogen on a volume basis thancryogenic liquid hydrogen), combined with the high content of water inthe fuel, water vapour in the air inlet and water combustion productsfrom the fuels (methanol and DME).

With this combustion reaction there will be an excess of water generatedand the opportunity exists to capture a portion of this for recycle andmixing with a lower-water content pre-mix fuel stored in the storagetank. In some embodiments it is advantageous to reduce supply chainlogistics costs associated with the presence of water in the fuel bytransporting a higher methanol content base fuel, and meeting targetengine quality at higher water levels by the capture of water from theengine exhaust.

A heat exchange and spray chamber arrangement using water that may havebeen purified with optional additives for selected species removal inthe final phase can be configured to ensure that non CO2 pollution fromthe combustion of methanol is close to nil. In addition a final cleanupof the exhaust gas may be obtained by adsorption of for example, unburntmethanol onto activated surfaces, for later desorption and recycle tothe engine within the process using known techniques, or forincorporating as part of the fumigant or main fuel.

In terms of SOX the exhaust gas in this case may have the followinganalysis:

-   -   SOX <0.1 ppm.

In general the emissions of other pollutants such as NOX particulateswill be much lower compared to oil based diesel fuels.

Any small amounts of NOX and SOX formed in the combustion phase, and theabsorption of CO₂ in the water phase, can result in weak acidificationof the water returning to mix with the fuel. The returning water mix mayneed chemical treatment or mechanical adjustment to offset this weakacidification.

The exhaust gas resulting from such cleanup has improved emissionscompared to diesel fuel in terms of hydrocarbon, particulate, NOX andSOX emissions, which is environmentally advantageous.

CO₂ Recovery

The exhaust resulting from the high water fuel contains almost noimpurities, making it ideal for subsequent processing. In particular,the CO₂ is converted back to methanol to directly reduce the greenhousegas CO₂ or high purity CO₂ can be used for organic growth such as algaefor multiple end uses including methanol manufacture, utilizing energysources which can include renewable sources, such as solar, and soforth.

By separating or purifying the oxygen level in air, nitrogen can bereduced or eliminated from the engine with the resultant reduction orelimination of NOX potential from the oxidation of nitrogen. Recyclingof exhaust CO₂ to the engine O₂ intake would allow optimization ofoxygen level entering the engine and the generation of a largely pureCO₂ and water vapour exhaust. This CO₂ is ideal for further processingto methanol or the above-mentioned applications if desired.

Example 7 Fuel Comprised of 10% Water:5% DME:85% Methanol by Weight withFumigant

Fumigant as 100% DME required at full load may be reduced to 1 to 2%range.

Example 8 Fuel Compositions and Fumigant Combinations

In the following table examples of methanol/water fuel compositions andcorresponding fumigant levels, which enable the smooth operation ofcombustion ignition engines, are outlined. The table is in two parts—themain fuel of each numbered line pairs with a suitable fumigant on thesame numbered line, although pairings between neighbouring fuels andfumigants are possible. Regarding the identity of the fuel extenders,lubricants, ignition improvers and other additives, these are selectedfrom the examples provided in the detailed description above. The %amount referred to in the table for these additives refers to the amountof a single additive of that description, or the total of the additivesof that description when a combination of more than one such additive ofthat class is used. Specific examples utilise sugar or fatty acid esteras fuel extender, fatty acid ester or ethanolamine derivate as lubricityadditive, ether as ignition enhancer, and product colour and flamecolour additives as the additional additive.

Various fumigants are indicated in the tables, some lower in theirignition properties than those classed as higher ignition components.The components listed are not exhaustive, other suitable componentslisted elsewhere in this document and known to those skilled in the artmay also be used.

Additives Additives Whole Fuel Basis (% Wt) Class 1 Additives Class 3Additives Water Methanol Additives Fuel Class 2 Ignition Class 4 % % %Extenders Lubricants Improvers Other MAIN FUEL 1. 0.2 91.15 8.65 0.151.5 5 2 2. 0.2 89.65 10.15 0.15 3 5 2 3. 0.2 87.65 12.15 0.15 5 5 2 4.0.2 91.15 8.65 0.15 1.5 5 2 5. 0.2 89.65 10.15 0.15 3 5 2 6. 0.2 81.6518.15 0.15 5 10 3 7. 0.2 85.15 14.65 0.15 1.5 10 3 8. 0.2 83.65 16.150.15 3 10 3 9. 0.2 81.65 18.15 0.15 5 10 3 10. 0.2 85.15 14.65 0.15 1.510 3 11. 1 82.85 16.15 0.15 3 10 3 12. 1 94.35 4.65 1.15 1.5 0 2 13. 190.85 8.15 2.15 3 0 3 14. 1 88.85 10.15 3.15 5 0 2 15. 1 90.35 8.65 4.151.5 0 3 16. 1 88.85 10.15 5.15 3 0 2 17. 1 79.85 19.15 6.15 5 5 3 18. 183.35 15.65 7.15 1.5 5 2 19. 1 79.85 19.15 8.15 3 5 3 20. 1 75.85 23.159.15 5 5 4 21. 5 73.35 21.65 10.15 1.5 5 5 22. 5 90.35 4.65 1.15 1.5 0 223. 5 87.85 7.15 2.15 3 0 2 24. 5 84.85 10.15 3.15 5 0 2 25. 5 82.3512.65 4.15 1.5 5 2 26. 5 79.85 15.15 5.15 3 5 2 27. 5 70.85 24.15 6.15 510 3 28. 5 73.35 21.65 7.15 1.5 10 3 29. 5 65.85 29.15 8.15 3 15 3 30. 562.85 32.15 9.15 5 15 3 31. 10 55.35 34.65 10.15 1.5 20 3 32. 10 82.857.15 1.15 3 0 3 33. 10 84.35 5.65 2.15 1.5 0 2 34. 10 80.85 9.15 3.15 30 3 35. 10 73.85 16.15 4.15 5 5 2 36. 10 75.35 14.65 5.15 1.5 5 3 37. 1068.85 21.15 6.15 3 10 2 38. 10 64.85 25.15 7.15 5 10 3 39. 10 63.3526.65 8.15 1.5 15 2 40. 10 59.85 30.15 9.15 3 15 3 41. 15 45.85 39.1510.15 5 20 4 42. 15 77.35 7.65 1.15 1.5 0 5 43. 15 79.35 5.65 2.15 1.5 02 44. 15 76.85 8.15 3.15 3 0 2 45. 15 68.85 16.15 4.15 5 5 2 46. 1571.35 13.65 5.15 1.5 5 2 47. 15 63.85 21.15 6.15 3 10 2 48. 15 59.8525.15 7.15 5 10 3 49. 15 57.35 27.65 8.15 1.5 15 3 50. 15 54.85 30.159.15 3 15 3 51. 20 41.85 38.15 10.15 5 20 3 52. 20 74.35 5.65 1.15 1.5 03 53. 20 71.85 8.15 2.15 3 0 3 54. 20 73.35 6.65 3.15 1.5 0 2 55. 2064.85 15.15 4.15 3 5 3 56. 20 62.85 17.15 5.15 5 5 2 57. 20 59.35 20.656.15 1.5 10 3 58. 20 57.85 22.15 7.15 3 10 2 59. 20 48.85 31.15 8.15 515 3 60. 20 52.35 27.65 9.15 1.5 15 2 61. 25 38.85 36.15 10.15 3 20 362. 25 64.85 10.15 1.15 5 0 4 63. 25 66.35 8.65 2.15 1.5 0 5 64. 2568.35 6.65 3.15 1.5 0 2 65. 25 60.85 14.15 4.15 3 5 2 66. 25 57.85 17.155.15 5 5 2 67. 25 55.35 19.65 6.15 1.5 10 2 68. 25 52.85 22.15 7.15 3 102 69. 25 43.85 31.15 8.15 5 15 3 70. 25 46.35 28.65 9.15 1.5 15 3 71. 3033.85 36.15 10.15 3 20 3 72. 30 60.85 9.15 1.15 5 0 3 73. 30 63.35 6.652.15 1.5 0 3 74. 30 60.85 9.15 3.15 3 0 3 75. 30 57.35 12.65 4.15 1.5 52 76. 30 53.85 16.15 5.15 3 5 3 77. 30 46.85 23.15 6.15 5 10 2 78. 3048.35 21.65 7.15 1.5 10 3 79. 30 41.85 28.15 8.15 3 15 2 80. 30 37.8532.15 9.15 5 15 3 81. 40 26.35 33.65 10.15 1.5 20 2 82. 40 38.85 21.155.15 3 10 3 83. 40 29.85 30.15 6.15 5 15 4 84. 40 26.35 33.65 7.15 1.520 5 85. 50 27.85 22.15 5.15 5 10 2 86. 50 24.35 25.65 6.15 1.5 15 3 87.50 17.85 32.15 7.15 3 20 2 88. 60 16.85 23.15 5.15 5 10 3 89. 60 18.3521.65 6.15 1.5 10 4 90. 60 17.85 22.15 7.15 5 5 5 91. 10 55.35 34.6510.15 1.5 20 3 92. 10 82.85 7.15 1.15 3 0 3 93. 10 84.35 5.65 2.15 1.5 02 94. 10 80.85 9.15 3.15 3 0 3 95. 10 73.85 16.15 4.15 5 5 2 96. 1075.35 14.65 5.15 1.5 5 3 97. 10 68.85 21.15 6.15 3 10 2 98. 10 64.8525.15 7.15 5 10 3 99. 10 63.35 26.65 8.15 1.5 15 2 100. 10 59.85 30.159.15 3 15 3 101. 15 45.85 39.15 10.15 5 20 4 102. 15 77.35 7.65 1.15 1.50 5 103. 15 79.35 5.65 2.15 1.5 0 2 104. 15 76.85 8.15 3.15 3 0 2 105.15 68.85 16.15 4.15 5 5 2 106. 15 71.35 13.65 5.15 1.5 5 2 107. 15 63.8521.15 6.15 3 10 2 108. 15 59.85 25.15 7.15 5 10 3 109. 15 57.35 27.658.15 1.5 15 3 110. 15 54.85 30.15 9.15 3 15 3 111. 20 41.85 38.15 10.155 20 3 112. 20 74.35 5.65 1.15 1.5 0 3 113. 20 71.85 8.15 2.15 3 0 3114. 20 73.35 6.65 3.15 1.5 0 2 115. 20 64.85 15.15 4.15 3 5 3 116. 2062.85 17.15 5.15 5 5 2 117. 20 59.35 20.65 6.15 1.5 10 3 118. 20 57.8522.15 7.15 3 10 2 119. 20 48.85 31.15 8.15 5 15 3 120. 20 52.35 27.659.15 1.5 15 2 121. 25 38.85 36.15 10.15 3 20 3 122. 25 64.85 10.15 1.155 0 4 123. 25 66.35 8.65 2.15 1.5 0 5 124. 25 68.35 6.65 3.15 1.5 0 2125. 25 60.85 14.15 4.15 3 5 2 126. 25 57.85 17.15 5.15 5 5 2 127. 2555.35 19.65 6.15 1.5 10 2 128. 25 52.85 22.15 7.15 3 10 2 129. 25 43.8531.15 8.15 5 15 3 130. 25 46.35 28.65 9.15 1.5 15 3 131. 30 33.85 36.1510.15 3 20 3 132. 30 60.85 9.15 1.15 5 0 3 133. 30 63.35 6.65 2.15 1.5 03 134. 30 60.85 9.15 3.15 3 0 3 135. 30 57.35 12.65 4.15 1.5 5 2 136. 3053.85 16.15 5.15 3 5 3 137. 30 46.85 23.15 6.15 5 10 2 138. 30 48.3521.65 7.15 1.5 10 3 139. 30 41.85 28.15 8.15 3 15 2 140. 30 37.85 32.159.15 5 15 3 141. 40 23.85 36.15 10.15 3 20 3 142. 40 50.85 9.15 1.15 5 03 143. 40 53.35 6.65 2.15 1.5 0 3 144. 40 50.85 9.15 3.15 3 0 3 145. 4047.35 12.65 4.15 1.5 5 2 146. 40 43.85 16.15 5.15 3 5 3 147. 40 36.8523.15 6.15 5 10 2 148. 40 38.35 21.65 7.15 1.5 10 3 149. 40 31.85 28.158.15 3 15 2 150. 40 27.85 32.15 9.15 5 15 3 151. 50 13.85 36.15 10.15 320 3 152. 50 40.85 9.15 1.15 5 0 3 153. 50 43.35 6.65 2.15 1.5 0 3 154.50 40.85 9.15 3.15 3 0 3 155. 50 37.35 12.65 4.15 1.5 5 2 156. 50 33.8516.15 5.15 3 5 3 157. 50 26.85 23.15 6.15 5 10 2 158. 50 28.35 21.657.15 1.5 10 3 159. 50 21.85 28.15 8.15 3 15 2 160. 50 17.85 32.15 9.15 515 3 161. 60 15.85 24.15 10.15 3 8 3 162. 60 30.85 9.15 1.15 5 0 3 163.60 33.35 6.65 2.15 1.5 0 3 164. 60 30.85 9.15 3.15 3 0 3 165. 60 27.3512.65 4.15 1.5 5 2 166. 60 23.85 16.15 5.15 3 5 3 167. 60 16.85 23.156.15 5 10 2 168. 60 18.35 21.65 7.15 1.5 10 3 169. 60 16.85 23.15 8.15 310 2 170. 60 17.85 22.15 9.15 5 5 3 171. 70 18 12 1 3 5 3 172. 70 20.859.15 1.15 5 0 3 173. 70 23.35 6.65 2.15 1.5 0 3 174. 70 20.85 9.15 3.153 0 3 175. 70 18.35 11.65 4.15 1.5 4 2 176. 70 17.85 12.15 5.15 3 5 3177. 70 18 12 6.15 5 10 2 178. 70 19 11 7.15 1.5 10 3 179. 70 18 12 8.153 15 2 180. 70 18 12 1 5 3 3

Lower Lower Ignition Higher Higher Higher Total Ignition LPG IgnitionIgnition Ignition Water Fumigant Methanol Butane DME DEE DIPE Water As a% of % in % in % in % in % in % in Heat Main Fuel Fumigant FumigantFumigant Fumigant Fumigant Fumigant Methods Comment 1. 1 0 100 0 no 2. 14 95 1 no 3. 1 13 85 2 no 1) 4. 1 17 80 3 no 5. 1 21 75 4 no 6. 1 25 705 no 7. 2 29 65 6 no 8. 2 33 60 7 no 2) 9. 1 2 90 8 no 10. 1 1 90 9 no11. 2 0 100 0 no 12. 2 4 95 1 no 13. 2 13 85 2 no 14. 2 17 * 80 3 no 15.2 21 75 4 no 16. 2 25 70 5 no 17. 2 29 65 6 no 18. 3 33 60 7 no 19. 2 290 8 no 20. 2 1 90 9 no 21. 2 0 100 0 no 22. 2 4 95 1 no 23. 2 13 85 2no 24. 3 17 80 3 no 25. 3 21 75 4 no 26. 3 25 70 5 no 27. 3 29 65 6 no28. 3 33 60 7 no 29. 2 2 90 8 no 30. 2 1 90 9 no 31. 3 0 100 0 no 32. 34 95 1 no 33. 4 13 85 2 no 34. 4 17 80 3 no 35. 4 21 75 4 no 36. 4 25 2050 5 no 37. 5 29 65 6 no 38. 5 33 60 7 no 39. 3 2 90 8 no 40. 3 1 90 9no 41. 4 0 100 0 no 42. 4 4 95 1 no 43. 5 13 85 2 no 44. 5 17 80 3 no45. 5 21 75 4 no 46. 6 25 70 5 no 47. 6 29 65 6 no 48. 7 33 60 7 no 49.4 2 90 8 no 50. 4 1 90 9 no 51. 5 0 100 0 no 52. 5 4 95 1 no 53. 6 13 852 no 54. 6 17 80 3 no 55. 7 21 75 4 no 56. 7 25 70 5 no 57. 8 29 65 6 no58. 8 33 60 7 no 59. 6 2 90 8 no 60. 6 1 90 9 no 61. 6 0 100 0 no 62. 64 95 1 no 63. 7 13 85 2 no 64. 8 17 80 3 no 65. 8 21 75 4 no 66. 9 25 705 no 67. 9 29 65 6 no 68. 10 33 60 7 no 69. 7 2 90 8 no 70. 7 1 90 9 no71. 8 0 100 0 no 72. 8 4 95 1 no 73. 9 13 85 2 no 74. 10 17 80 3 no 75.11 21 75 4 no 76. 11 25 70 5 no 77. 12 29 65 6 no 78. 13 33 60 7 no 79.9 2 90 8 no 80. 9 1 90 9 no 81. 11 0 100 0 no 82. 12 8 90 2 no 83. 13 1385 2 no 84. 12 3 95 2 no 85. 14 0 100 0 no 86. 16 13 85 2 no 87. 15 3 952 no 88. 19 0 100 0 no 89. 19 0 100 0 no 90. 19 0 100 0 no 91. 1 0 100 0yes 92. 1 4 95 1 yes 93. 1 13 85 2 yes 94. 1 17 80 3 yes 95. 1 21 75 4yes 96. 1 25 70 5 yes 97. 2 29 65 6 yes 98. 2 33 60 7 yes 99. 1 2 90 8yes 100. 1 1 90 9 yes 101. 1 0 100 0 yes 102. 1 4 95 1 yes 103. 2 13 852 yes 104. 2 17 80 3 yes 105. 2 21 75 4 yes 106. 2 25 70 5 yes 107. 2 2965 6 yes 108. 2 33 60 7 yes 109. 1 2 90 8 yes 110. 1 1 90 9 yes 111. 2 0100 0 yes 112. 2 4 95 1 yes 113. 2 13 85 2 yes 114. 2 17 80 3 yes 115. 221 75 4 yes 116. 2 25 70 5 yes 117. 3 29 65 6 yes 118. 3 33 60 7 yes119. 2 2 90 8 yes 120. 2 1 90 9 yes 121. 2 0 100 0 yes 122. 2 4 95 1 yes123. 2 13 85 2 yes 124. 3 17 80 3 yes 125. 3 21 75 4 yes 126. 3 25 70 5yes 127. 3 29 65 6 yes 128. 3 33 60 7 yes 129. 2 2 90 8 yes 130. 2 1 909 yes 131. 3 0 100 0 yes 132. 3 4 95 1 yes 133. 3 13 85 2 yes 134. 3 1780 3 yes 135. 4 21 75 4 yes 136. 4 25 70 5 yes 137. 4 29 65 6 yes 138. 433 60 7 yes 139. 3 2 90 8 yes 140. 3 1 90 9 yes 141. 4 0 100 0 yes 142.4 4 95 1 yes 143. 4 13 85 2 yes 144. 5 17 80 3 yes 145. 5 21 75 4 yes146. 5 25 70 5 yes 147. 6 29 65 6 yes 148. 6 33 60 7 yes 149. 4 2 90 8yes 150. 4 1 90 9 yes 151. 5 0 100 0 yes 152. 5 4 95 1 yes 153. 5 13 852 yes 154. 6 17 80 3 yes 155. 6 21 75 4 yes 156. 7 25 70 5 yes 157. 7 2965 6 yes 158. 8 33 60 7 yes 159. 5 2 90 8 yes 160. 5 1 90 9 yes 161. 6 0100 0 yes 162. 7 4 95 1 yes 163. 7 13 85 2 yes 164. 8 17 80 3 yes 165. 821 75 4 yes 166. 9 25 70 5 yes 167. 10 29 65 6 yes 168. 11 33 60 7 yes169. 7 2 90 8 yes 170. 7 1 90 9 yes 171. 9 0 100 0 yes 172. 9 4 95 1 yes173. 11 13 85 2 yes 174. 11 17 80 3 yes 175. 12 21 75 4 yes 176. 13 2570 5 yes 177. 14 29 65 6 yes 178. 15 33 60 7 yes 179. 10 2 90 8 yes 180.10 1 90 9 yes ^(Δ)% by weight; additional to the 100% water/methanolcombination *by weight of total fuel intake

1. A process of powering a compression ignition engine using a main fuelcomprising methanol and water, including: fumigating an intake airstream with a fumigant comprising an ignition enhancer; introducing thefumigated intake air into a combustion chamber in the engine andcompressing the intake air; introducing the main fuel comprisingmethanol and at least 3% by weight water, and not more than 20% byweight dimethyl ether into the combustion chamber; and igniting the mainfuel/air mixture to thereby drive the engine.
 2. The process of claim 1,including fumigating the intake air with the fumigant to an amount of0.5%-70% wt of main fuel.
 3. (canceled)
 4. The process of claim 1,including fumigating with a fumigant comprising an ether as the ignitionenhancer.
 5. The process of claim 4, including fumigating with afumigant comprising dimethyl ether.
 6. The process of claim 1, includingintroducing a main fuel comprising water and methanol in a ratio ofbetween 0.2:99.8 to 80:20 into the combustion chamber.
 7. The process ofclaim 1, including introducing a main fuel comprising between 12% and23% water, methanol, and not more than 20% by weight of additives. 8.The process of claim 1, including introducing a main fuel comprisingbetween 20% and 68% by weight water, methanol, and not more than 20% byweight of additives. 9-10. (canceled)
 11. The process of claim 1,wherein the main fuel comprises one or more additives selected from thegroup consisting of: ignition improvers, fuel extenders, combustionenhancers, oxygen absorbing oil, lubricity additives, productcolouration additives, flame colour additives, anti corrosion additives,biocides, freeze point depressants, deposit reductants, denaturants, pHcontrolling agents, and mixtures thereof.
 12. The process of claim 1,wherein the main fuel comprises a crude methanol and up to 60% non-wateradditives, or the main fuel comprises a refined methanol and up to 25%non-water additives.
 13. The process of claim 1, including preheatingthe intake air in the combustion chamber before feeding the main fuelinto the combustion chamber.
 14. The process of claim 13, includingpre-heating the intake air to at least 130° C.
 15. The process of claim1, including producing the ignition enhancer by catalytic conversion ofmethanol in a stream of the main fuel composition.
 16. The process ofclaim 1, including providing a pre-fuel comprising methanol and ether asignition enhancer, separating the ignition enhancer from the pre-fuel,fumigating the intake air stream with the ignition enhancer separatedfrom the pre-fuel, and introducing the balance of the pre-fuel followingseparation of the ignition enhancer into the combustion chamber as themain fuel. 17-18. (canceled)
 19. A compression ignition engine fuel foruse in a compression ignition engine which is fumigated with a fumigantcomprising an ignition enhancer into an air inlet of the engine, thefuel comprising methanol and at least 3% by weight water, and one ormore additives selected from the group consisting of: ignitionimprovers, fuel extenders, combustion enhancers, oxygen absorbing oil,lubricity additives, product colouration additives, flame colouradditives, anti corrosion additives, biocides, freeze point depressants,deposit reductants, denaturants, pH controlling agents, and mixturesthereof, wherein the fuel comprises not more than 20% by weight dimethylether.
 20. The fuel of claim 19, wherein the fuel comprises from 3% to40% water, and not more than 20% dimethyl ether.
 21. The fuel of claim19, wherein the additives comprise: a product colouration additive at upto 1% by weight, and a flame colour additive, at up to 1% by weight ofthe fuel. 22-40. (canceled)
 41. A method of transporting a pre-fuelcomposition comprising methanol and ether, including transporting thepre-fuel from a first location to a second location remote from thefirst location, and separating the ether from the methanol to yield afirst fuel part comprising methanol and not more than 20% by weightether, and a second fuel part comprising ether.
 42. The method of claim41, wherein the ether is dimethyl ether. 43-45. (canceled)
 46. Theprocess of claim 1, wherein the main fuel composition comprises from 5%to 40% by weight water, methanol, and not more than 20% by weightdimethyl ether.